1.www.4411b.com
www.4411b.com 时间:2021-03-17 阅读:()
RESEARCHARTICLEDeletionsofNRXN1(Neurexin-1)PredisposetoaWideSpectrumofDevelopmentalDisordersMichaelS.
L.
Ching,1,2YipingShen,2,3,7Wen-HannTan,2,4ShafaliS.
Jeste,2,5EricM.
Morrow,6XiaoliChen,7,8NahitM.
Mukaddes,9Seung-YunYoo,4EllenHanson,1,2RachelHundley,1,2ChristinaAustin,4RonaldE.
Becker,1,2GerardT.
Berry,2,4KatherineDriscoll,1,2ElizabethC.
Engle,2,5,10,11,12SandraFriedman,1,2JamesF.
Gusella,2,3,13FukiM.
Hisama,2,4MiraB.
Irons,2,4TinaLaosca,1,2ElaineLeClair,1,2DavidT.
Miller,2,4,7MichaelNeessen,1,2JonathanD.
Picker,2,4LeonardRappaport,1,2CynthiaM.
Rooney,2,5DeanP.
Sarco,2,5JoanM.
Stoler,2,4ChristopherA.
Walsh,2,4,11,14RobertR.
Wolff,2,5TingZhang,8RamziH.
Nasir,1,2*Bai-LinWu2,7,15**onbehalfoftheChildren'sHospitalBostonGenotypePhenotypeStudyGroup1DivisionofDevelopmentalMedicine,Children'sHospitalBoston,Boston,Massachusetts2HarvardMedicalSchool,Boston,Massachusetts3CenterforHumanGeneticResearch,MassachusettsGeneralHospital,Boston,Massachusetts4DivisionofGenetics,Children'sHospitalBoston,Boston,Massachusetts5DepartmentofNeurology,Children'sHospitalBoston,Boston,Massachusetts6DepartmentofMolecularBiology,CellBiologyandBiochemistry,BrownUniversity,Providence,RhodeIsland7DepartmentofLaboratoryMedicine,Children'sHospitalBoston,Boston,Massachusetts8DepartmentofMolecularImmunology,CapitalInstituteofPediatrics,Beijing,China9IstanbulFacultyofMedicine,DepartmentofChildPsychiatry,IstanbulUniversity,Istanbul,Turkey10Children'sHospitalBoston,HowardHughesMedicalInstitute,Boston,Massachusetts11MantonCenterforOrphanDiseaseResearch,Children'sHospitalBoston,Boston,Massachusetts12DepartmentofOphthalmology,Children'sHospitalBoston,Boston,Massachusetts13DepartmentofGenetics,HarvardMedicalSchool,Boston,Massachusetts14HowardHughesMedicalInstitute,BethIsraelDeaconessMedicalCenter,Boston,Massachusetts15Children'sHospitalandInstitutesofBiomedicalScience,FudanUniversity,Shanghai,ChinaReceived1July2009;Accepted15December2009AdditionalSupportingInformationmaybefoundintheonlineversionofthisarticle.
TheChildren'sHospitalBostonGenotypePhenotypeStudyGroupalsoincludesOmarS.
Khwaja,AnnapurnaPoduri,MustafaSahinandMagdiSobeih,DepartmentofNeurology,Children'sHospitalBoston,HarvardMedicalSchool,Boston,Massachusetts.
Grantsponsors:NancyLurieMarksFamilyFoundation;SimonsFoundation;AutismSpeaks;NIH;Grantnumbers:5K23MH080954-02,1R01MH083565.
M.
S.
L.
ChingandY.
Shencontributedequallytothiswork.
*Correspondenceto:RamziH.
Nasir,DivisionofDevelopmentalMedicine,Children'sHospitalBoston,HarvardMedicalSchool.
300LongwoodAve.
,Boston,MA02115.
E-mail:ramzi.
nasir@childrens.
harvard.
edu**Correspondenceto:Bai-LinWu,DepartmentsofLaboratoryMedicineandPathology,Children'sHospitalBoston,HarvardMedicalSchool.
300LongwoodAve.
,Boston,MA02115.
E-mail:bai-lin.
wu@childrens.
harvard.
eduPublishedonline7April2010inWileyInterScience(www.
interscience.
wiley.
com)DOI10.
1002/ajmg.
b.
310632010Wiley-Liss,Inc.
937NeuropsychiatricGeneticsResearchhasimplicatedmutationsinthegeneforneurexin-1(NRXN1)inavarietyofconditionsincludingautism,schizo-phrenia,andnicotinedependence.
Toourknowledge,therehavebeennopublishedreportsdescribingthebreadthofthepheno-typeassociatedwithmutationsinNRXN1.
WepresentamedicalrecordreviewofsubjectswithdeletionsinvolvingexonicsequencesofNRXN1.
Weascertainedcasesfrom3,540individ-ualsreferredclinicallyforcomparativegenomichybridizationtestingfromMarch2007toJanuary2009.
Twelvesubjectswereidentiedwithexonicdeletions.
ThephenotypeofindividualswithNRXN1deletionisvariableandincludesautismspectrumdisorders,mentalretardation,languagedelays,andhypotonia.
TherewasastatisticallysignicantincreaseinNRXN1deletioninourclinicalsamplecomparedtocontrolpopulationsdescribedintheliterature(P8.
9107).
ThreeadditionalsubjectswithNRXN1deletionsandautismwereidentiedthroughtheHomozygosityMappingCollaborativeforAutism,andthisdeletionsegregatedwiththephenotype.
OurstudyindicatesthatdeletionsofNRXN1predisposetoawidespectrumofdevelopmentaldisorders.
2010Wiley-Liss,Inc.
Keywords:NRXN1(neurexin-1);developmentaldisorders;arrayCGH;NRXN1exonicdeletions;CNVINTRODUCTIONNeurexinsareagroupofhighlypolymorphiccellsurfaceproteinsinvolvedinsynapseformationandsignaling[Ushkaryovetal.
,1992;MisslerandSudhof,1998;Missleretal.
,2003;Grafetal.
,2004;NamandChen,2005].
Therearethreehumanneurexingenes(NRXN1,NRXN2,andNRXN3),eachofwhichhastwoindepen-dentpromotersresultinginanaandabneurexinforeachgene[Ushkaryovetal.
,1992;Ichtchenkoetal.
,1996].
Multiplealterna-tivesplicingleadstothepossibilityofgreaterthanathousanddistinctneurexinisoforms[Ullrichetal.
,1995].
Theirexpressionisbelievedtobespatiallyandtemporallyregulatedthroughoutdevelopment[PuschelandBetz,1995;Zengetal.
,2006].
StructureandFunctionofNRXN1NRXN1,locatedonchromosome2p16.
3,isoneofthelargestknownhumangenes(1.
1Mbwith24exons)[TabuchiandSudhof,2002].
Itissubjecttorelativelyfrequentdisruptionincludingmissensechanges,translocation,wholegenedeletion,andintra-geniccopynumberalterations[Fengetal.
,2006;Szatmarietal.
,2007;InternationalSchizophreniaConsortium,2008;Kimetal.
,2008;Kirovetal.
,2008;Marshalletal.
,2008;Morrowetal.
,2008;Yanetal.
,2008;Zahiretal.
,2008;Glessneretal.
,2009;Rujescuetal.
,2009].
Thelongertranscript,NRXN1-a,encodesanN-terminalsignalpeptidewiththreerepeatsoftwolaminin/neurexin/sexhormone-bindingglobulin(LNS)domainsseparatedbyanEGF-likesequence(Fig.
1).
Followingtheserepeats,thereisanO-glycosyla-tionsequence,atransmembranedomain,andacytoplasmictailof55aminoacids.
Neurexin-1-ahasbeenshowntointeractwithcertainneuroliginisoformsandneurexin-bindingproteinsknownasneurexophilins.
Thispresynapticmoleculeisalsorequiredforcalcium-triggeredneurotransmitterreleaseandthefunctionofvoltage-gatedcalciumchannelsinthesynapsesofthebrainstemandneocortex[Missleretal.
,2003;Zhangetal.
,2005;Dudanovaetal.
,2006].
Mouseknockoutsofallthreea-neurexingenesdonotdemonstratemajorabnormalitiesofaxonalpathndingduringdevelopment[Dudanovaetal.
,2007],althoughsynapticfunctionisseverelyimpaired.
Micewithknockoutsofindividuala-neurexingeneshavemodestlydecreasedpostnatalviability,whiledoubleknockoutmicehavegreatlydecreasedpostnatalsurvival.
Tripleknockoutmicedonotsurvivepasttherstdayoflife[Missleretal.
,2003].
Neurexin-1-bismuchshorterthanNeurexin-1-a,asveofthesixLNSdomainsandtheinterveningEGFsequencesarereplacedwithashortb-neurexin-specicsequence(Fig.
1)[MisslerandSudhof,1998].
Neurexin-1-bhasbeenshowntointeractwiththepostsynapticneuroliginfamilyofcelladhesionmoleculesanddystroglycans[Ichtchenkoetal.
,1995;Sugitaetal.
,2001;Aracetal.
,2007;Comolettietal.
,2007;Chenetal.
,2008].
NomousemodelswithknockoutsofNRXN1-b,aloneorincombinationwithNRXN1-a,haveyetbeenanalyzed[Sudhof,2008].
ForeachofNeurexin-1-aandNeurexin-1-b,multipleproteincodingisoformsofNRXN1havebeenidentied,whosestructureandfunctionsarenotwellunderstood.
NRXN1MutationsinHumansThereisincreasingevidencethatNRXN1disruptions[Kimetal.
,2008],pointmutations[Fengetal.
,2006;Yanetal.
,2008],anddeletions[Glessneretal.
,2009;Marshalletal.
,2008;Morrowetal.
,2008;Szatmarietal.
,2007]areassociatedwithautismspectrumdisorders.
NRXN1hasalsobeenfoundtobeassociatedwithautisminalargegenome-widesinglenucleotidepolymorphismassocia-tionstudy[Wangetal.
,2009].
NRXN1deletionshavealsobeenassociatedwithavarietyofotherconditionsincludingschizophrenia[InternationalSchizophreniaConsortium,2008;Kirovetal.
,2008;Vrijenhoeketal.
,2008;Walshetal.
,2008;Needetal.
,2009;Rujescuetal.
,2009],nicotinedependence[Bierutetal.
,2007;Nussbaumetal.
,2008],HowtoCitethisArticle:ChingMSL,ShenY,TanW-H,JesteSS,MorrowEM,ChenX,MukaddessNM,YooS-Y,HansonE,HundleyR,AustinC,BeckerRE,BerryGT,DriscollK,EngleEC,FriedmanS,GusellaJF,HisamaFM,IronsMB,LaoscaT,LeClairE,MillerDT,NeessenM,PickerJD,RappaportL,RooneyCM,SarcoDP,StolerJM,WalshCA,WolffRR,ZhangT,NasirRH,WuB-L,onbehalfoftheChildren'sHospitalBostonGenotypePhenotypeStudyGroup.
2010.
DeletionsofNRXN1(Neurexin-1)PredisposetoaWideSpectrumofDevelopmentalDisorders.
AmJMedGenetPartB153B:937–947.
938AMERICANJOURNALOFMEDICALGENETICSPARTBandotherphysicalmanifestationssuchasvertebralanomalies[Zahiretal.
,2008].
PriorreportsofabnormalitiesinNRXN1havefocusedonpopulationswithspecicdiagnoses(e.
g.
,autism,schizophrenia).
However,theclinicalsignicanceofcopynumbervariants(CNV),suchasdeletioninvolvingoneormoreexonsofNRXN1,andtherangeofphenotypicmanifestationsofsubjectswithNRXN1dele-tionCNVremainsunclear.
WedescribehereagroupofsubjectswithNRXN1deletionswhodemonstrateawiderangeofphysicalanddevelopmentalphenotypes.
MATERIALSANDMETHODSClinicalCohortRecordReviewFromMarch2007toJanuary2009,atotalof3,540subjectsatChildren'sHospitalBostonwereevaluatedforgenomicimbalance(deletionandduplication)usingtheAgilent244Khumangenomeoligonucleotidecomparativegenomichybridization(CGH)mi-croarrays(G4411B,AgilentTechnologies,PaloAlto,CA)accordingtothemanufacturer'sinstructions[OligonucleotideArray-BasedCGHforGenomicDNAAnalysisprotocolversion3(AgilentTechnologies)].
Themajorityofthereferralswereforclinicalfeaturesofdevelopmentaldisorders(developmentaldelay,autismspectrumdisorders,mentalretardation)ormultiplecongenitalmalformationsasdeterminedbyspecialistsinClinicalGenetics,Neurology,andDevelopmentalMedicine.
Onehundredthirtyprobescoverthe1.
12MbregionoftheNRXN1geneontheAgilent244KCGHarray.
Theaverageinterp-robespacewithintheNRXN1geneis8.
6kb.
Thispermitsthereliabledetectionofsmallintragenicdeletionsdownto43kbinsize.
ImageswerecapturedbyAgilentscannerandquantiedusingFeatureExtractionsoftwarev9.
0(AgilentTechnologies).
CGHAnalyticsSoftwarev3.
4(AgilentTechnologies)wassubsequentlyusedfordatanormalization,qualityevaluationanddatavisualiza-tion.
CopynumberaberrationwasindicatedusingtheAberrationDetectionMethod2(ADM-2)algorithm.
DeletionsinvolvingveormoreconsecutiveprobeswereconsideredastrueCNV.
Fortwolargerdeletions,uorescentinsituhybridization(FISH)testingusingprobeRP11-800C7wascarriedoutfordeletionconrmationandparentaltesting.
ThesmallerdeletionswereconrmedbyPCR-basedbreakpointmappingmethods.
Thepri-mersusedforeachcasearelistedintheSupplementaryMaterial.
SubjectswithdeletionsinvolvingexonicsequenceofNRXN1wereincludedinourreview.
Twodevelopmentalbehavioralpedia-tricians(RHN,MSLC),aclinicalgeneticist(WHT),andapediatricneurologist(SSJ)reviewedeachofthemedicalrecords.
Theclinicalhistory,physicalexamination,laboratorydata,andradiologicalreportsofeachsubjectwerereviewed.
AdditionalReportofCasesWithNRXN1DeletionandAutismCaseswithexonicandintragenicNRXN1deletionswerealsocontributedfromtheHomozygosityMappingCollaborativeforAutism(HMCA)whichutilizedtheAffymetrixGeneChipHumanMapping500KArraySetusingCNVdetectionmethodspreviouslydescribed[Morrowetal.
,2008].
ThisworkwasapprovedbytheInstitutionalReviewBoardsatthecorrespondinghospitals.
RESULTSClinicalCohortRecordReviewWeidentied12subjectsthroughChildren'sHospitalBostonwithdeletionsinvolvingexonicsequencesofNRXN1(TableIandFig.
1).
Thedeletionsreportedhererangefrom65kbto5Mbandmostofthesecasesarepredictedtoaffecttheinitialstructuraldomainsoftheprotein(Fig.
1).
FIG.
1.
Illustratesthesizeandrangeofthe12deletionCNVsinrelationtotheexonsandproteindomainsofNRXN1-aand-bintheUCSCGenomeBrowser(http://genome.
ucsc.
edu)[Kentetal.
,2002].
Thetoptrackshowsthegenomicpositionandsizeofthe12deletionCNVs.
ThemiddletracksshowthegeneannotationsinRefSeqandEnsembl.
TheRefseqGenesshowtheaandbisoformsoftheNRXN1gene;theEnsemblgenepredictionshowsseveralotherminorisoformsoftheNRXN1gene.
ThebottompanelshowstheproteindomainsoftheNRXN1-ageneproduct.
SP,signalpeptide;LNS,laminin/neurexin/sexhormone-bindingglobulindomain;EGF,epitheliumgrowthfactorlikedomain;OS,O-glycosylationsequence;TM,transmembranedomain;CT,cytoplasmictail.
tail.
[Colorgurecanbeviewedintheonlineissue,whichisavailableatwww.
interscience.
wiley.
com.
]CHINGETAL.
939TABLEI.
DeletionsWithinNRXN1inOurSamplePatientDeletionlocation(hg18build)Sizeofdeletion(kb)InheritanceExons–intronsdeletedOthergenetictestsandresults(additionalimbalance)IndicationfortestingConrmationmethod146,938,685–52,015,8855,077MaternalFISHnormal;paternalstudyunavailableAllKaryotypingandFragileXtest:normal(contiguousdeletionincludingFSHR,LHCGR,STN1)ModeratementalretardationFISH250,128,256–54,050,7133,923DenovoAllexceptthelasttwoexonsNoneGlobaldevelopmentaldelays,suspectedautismFISH350,897,002–51,212,385315PaternalExon1–5;partialintron5Karyotypingandchromosome15methylation:normalGrossmotordelay,hypotoniaPCR450,936,914–51,167,934231PaternalExon1–5;partialintron5Karyotyping,fragileXtest,SALL1,andCHD7mutationtest:normalPDD-NOS,hypotoniaPCR550,920,082–51,059,469139DenovoExon3,4,5;partialintrons2,5NoneVACTERLNotdone651,059,410–51,316,396257MaternalExon1,2;partialintron2KaryotypingandfragileXtest:normalPDD-NOS,motorcoordinationdelaysPCR751,090,504–51,212,385122PaternalExon1–3;partialintron3Karyotyping,FragileXtest,andPTENmutationtest:normalAutism,moderatementalretardationPCR850,522,892–50,827,767305DenovoExon6–17;partialintrons5,17aFragileXtest:normal(deletionat3p24.
3from21492764to21806824,maternallyinherited)MildmentalretardationPCR950,689,280–50,853,329164Unknown(fosterfamily)Exon6–8;partialintrons5,8aKaryotyping:normalLanguagedelay,prenatalsubstanceexposurePCR1050,714,297–50,853,329139DenovoIntron5aKaryotypingandfragileXtest:normalPDD-NOSPCR1150,735,499–50,811,01876MaternalIntron5aKaryotyping,PTEN,andNSD1mutationtests:normal(duplicationsat5p13.
2from37241141to37758854,paternallyinherited;at15q26.
3from98059710to98842423,maternallyinherited;at17p11.
2from21147675to21442522maternallyinherited)Hypotonia,muscleweakness,largebirthweightPCR1250,735,499–50,801,23366MaternalIntron5aNonePoorweightgain,mildcraniofacialdysmorphismPCRFSHR,follicle-stimulatinghormonereceptor;LHCGR,luteinizinghormone/choriogonadotropinreceptor;STN1,StonedB-likefactor;PDD-NOS,pervasivedevelopmentaldisorder,nototherwisespecied;VACTERL,vertebralanomalies,analatresia,cardiacmalformations,tracheoesophagealstula,renalanomalies,andlimbanomalies;SALL1,sal-like1(Drosophila);CHD7,chromodomainhelicaseDNA-bindingprotein7;PTEN,phosphataseandtensinhomolog;NSD1,nuclearreceptor-bindingSETdomainprotein1.
aDeletionsofintron5inthesepatientsinvolveanexonofaminorisoformofNRXN1.
940AMERICANJOURNALOFMEDICALGENETICSPARTBOfthese12deletions,4weredenovoCNVnotidentiedineitherparent,3werematernallyinherited,3werepaternallyinherited,andtheparentalsamplesfor1(subject9)werenotavailable.
Insubjects1,paternalsampleswerenotavailablebutthedeletionwasnotidentiedinmaternaltesting.
Insubjects1–9,thedeletionsinvolvedatleasttwoexonsofNRXN1-a,whileinsubjects10–12,thedeletionsinvolvedonlyanexonofaminorexpressedNRXN1isoform.
Thegenomicimbal-ancesinvolvingNRXN1aresummarizedinTableIandtheclinicalmanifestationsaresummarizedinTablesIIandIII.
FurtherclinicaldataareavailableintheSupplementaryMaterial.
Detailedclinicalrecordswereavailablefromgeneticistsin9outof12subjects,developmental-behavioralpediatriciansin6/12,psychologistsin6/12,andneurologistsin4/12.
Fourofthe12subjects(4,6,7,and10)werediagnosedwithautismspectrumdisorders;ineachpositivecase,thisdiagnosiswassupportedbytheAutismDiagnosticObservationSchedule.
Anothersubject(2)wassuspectedofhavingautismbuttheevaluationwasnotavailableforreview;healsohadglobaldevelopmentaldelays.
Twosubjectshadmentalretardationwithoutadiagnosisofanautismspectrumdisorder(1and8).
Subject1,inaddition,hadabsenceseizuresandanEEGconsistentwithaprimarygeneralizedepilepsy.
Onesubject(3)wastooyoungtoascertainforanautismspectrumdisorderorcognitivedelays.
Ninesubjectshadclinicaldocumentationofexpressiveorreceptivelanguagedelays.
Milddysmorphicfeatureswerepresentinsevensubjects(2,3,4,7,8,9,and12);threesubjectshadhemangiomas(2,6,and10).
Hypotoniawaspresentinfoursubjects(3,4,9,and11).
Twosubjects(5and12)hadventricularseptaldefects.
MedicalrecordreviewalsorevealedthefollowingcharacteristicsinthesixparentsfromwhomtheNRXN1deletionwasinherited.
Subject4,whohadpervasivedevelopmentaldisorder,notother-wisespecied(PDD-NOS)andhypotonia,inheritedhisdeletionfromhisfatherwhoisalsoreportedtobesociallyawkward.
Subject6,whohadPDD-NOSandcoordinationissues,inheritedthedeletionfromamotherwithahistoryoflanguagedelayandsocialskilldifculties.
Subject11,whohashypotonia,weakness,andPolandanomaly,inheritedthedeletionfromamotherwhohasahistoryofjointhypermobility,osteoarthritis,mitralvalveprolapse,severemigraines,andseverebreastasymmetry.
Thefatherofsubject3(hypotonia,grossmotordelay),thefatherofsubject7(autism,mentalretardation)andthemotherofsubject12(poorweightgain,craniofacialdysmorphism)arereportedtobehealthywithoutdevelopmentalormedicalconcerns.
AdditionalReportofCasesWithNRXN1DeletionandAutismInadditiontotheChildren'sHospitalBostoncases,wereportherethreecasesfromtwofamiliesascertainedthroughtheHMCA[Morrowetal.
,2008].
TheNRXN1deletionsineachwerediscov-eredtosegregatewithIQbelow70inthesepedigrees(Fig.
2).
Allthreeaffectedchildrenwerecarriersandunaffectedchildrenwerenot.
ThedeletionswereinheritedfromfatherswhowerefoundtohaveASDsymptomsandIQbetween60and70,whilenon-carriermotherswerenotontheautismspectrumandwithIQsinthenormalrange.
Thedeletionforthesubjectintherstfamilyisexonicandintragenic,whilethedeletionforthetwosiblingsinthesecondfamilyisupstreamandmayaffectgeneexpression.
Furtherinvestigationisnecessarytosubstantiatethisasafunctionaldele-tion,eventhoughitsegregateswithdisease.
SignicanceTestToestablishtherelevanceoftheseCNV,wecomparedthefrequencyofdeletionsinvolvingNRXN1-aexonsinourChildren'sHospitalBostonpopulation,inwhomCGHtestingwasconsideredtobeclinicallyindicated,tothefrequencyofsimilardeletionsdetectedbyarraygenomicprolingofequivalentresolutioninnormalpop-ulations.
Itsaraetal.
[2009]detectedthreedeletionsinvolvingNRXN1-aexonsin2,493normalindividuals.
TheInternationalSchizophreniaConsortium[2008]reportedtwoexonicdeletioncasesin3,181normalcontrols.
Anotherlarge-scaleschizophreniastudyidentiedvedeletioncasesamong33,746normalcontrols[Rujescuetal.
,2009].
Recently,Glessneretal.
[2009]reportednodeletionCNVinvolvingNRXN1-aamong1,409AutismCase–Control(ACC)controlsamplesand1,110AutismGeneticResourceExchange(AGRE)controls.
Collectively,thefrequencyofexonicdeletionofNRXN1-aincontrolpopulationsis10/51,939(0.
019%);thisdifferssignicantlyfromthefrequencyofexonicdeletionCNVweobservedinourclinicallyreferredpopulation(9/3,540)(0.
25%;P8.
9107,two-tailedFisher'sexacttest).
Therearenoavailabledataonthefrequencyofminorisoformexonicdeletionsincontrolpopulationsandthusthesesubjects(n3)wereexcludedfromthesignicancetest.
DISCUSSIONTherecentrecognitionofgenomicimbalanceinmanychromo-somalregionsthatareassociatedwithautism,mentalretardation,andschizophreniaisduetotheincreasinguseofwholegenomehigh-resolutionarrayCGHintheevaluationofindividualswiththesedisorders.
OurclinicalsubjectswithNRXN1deletionwereascertainedthroughapatientpopulationpresentingwithabroadrangeofreferringdiagnoses.
Throughacarefulreviewofmedicalrecords,weidentiedinoursubjectsanumberofclinicalfeaturesthathadnotbeenpreviouslyassociatedwithNRXN1deletions.
Theseincludelanguagedelays,mentalretardationwithoutautism,hypotonia,andhemangiomas.
Inaddition,twoofoursubjects(5and12)hadventricularseptaldefects.
Interestingly,thehumancDNAhomologoustoratNRXN1-ahasbeenisolatedinbothbrainandhearttissuessuggest-ingapotentialroleforNeurexin-1inbothbrainandheartdevel-opment[Nagaseetal.
,1998].
Oneofthesesubjects(5)alsohadevidenceofmultiplecongenitalanomaliesincludingvertebralanomaliesintheformofaVACTERLassociation.
Vertebralanomalieshavealsobeenreportedinoneothercaseintheliterature[Zahiretal.
,2008].
Apreviousreportshowedthepresenceofaseizuredisorderintwounrelatedindividualssharingthesamemissensevariantinexon1ofNRXN1-b[Fengetal.
,2006].
Inourcohort,onlyonesubjecthadaseizuredisorder(subject1),althoughhis5MbdeletionencompassedtheentireNRXN1geneaswellasthegenesforfollicle-stimulatinghormonereceptor(FSHR),luteinizingCHINGETAL.
941TABLEII.
NeurologicalandDevelopmentalCharacteristicsSubjectSexAgeatascertainmentAutismspectrumdisorderCognitive-developmentalndingsLanguagedelayMotorinvolvementHistoryofseizures/EEGresultsMRI-brainBehavioralfeatures1M16yNoMR;SB5:FSIQ44;VIQ44;NVIQ48;(CA14y)ExpressiveandreceptiveWalkedat18monthsHistoryofseizures;abnormalEEGNormalInattention,impulsivity,hyperactivity2M2yAutismsuspected,noformalevaluationavailableGlobaldevelopmentaldelaysExpressiveandreceptiveNotdocumentedNotdocumentedNotperformedornotdocumentedNotdocumented3F10moNotsuspectedNoconcernsreported.
TestingnotdocumentedNoMildgrossmotordelay,hypotoniaNoneNotperformedornotdocumentedNotdocumented4M4yPDD-NOS(ADOS)WPPSI-IIIVIQ77,PIQ98(CA4y)ExpressiveHypotoniaEEGNormalNotperformedornotdocumentedAttentionconcerns5F6yNoNoconcernsreported.
Testingnotdocumented6monthreceptivedelayNormalNotdocumentedNotperformedornotdocumentedNotdocumented6F7yPDD-NOS(ADOS)BayleyIImentalscale91,29mo(CA31mo)ExpressiveMotorcoordinationdisorderNoneNotperformedornotdocumentedNotdocumented7M14yAutism(ADOS)MR:SB5:FSIQ47;VIQ46;NVIQ53ExpressiveandreceptiveNormalEEGnormalNotperformedornotdocumentedHyperactivity8F11yNoMR:WISC-IV:VCI67,PRI63,WMI59,PSI75,FSIQ58(CA11y)ExpressiveandreceptiveNormalNoneNormalInattention,dgety,disorganized9F4yNoAcademicdelaysreported.
TestingnotdocumentedExpressiveandreceptiveHypotoniaNoneNormalImpulsivityandinattention10M2yPDD-NOS(ADOS)BayleyIIIcognitivescore95(average)ExpressiveandreceptiveNormalNotdocumentedNotperformedornotdocumentedNotdocumented11M8yNoNoconcernsreported.
TestingnotdocumentedNoProximalanddistalweakness,hypotoniaNoneNotperformedornotdocumentedNotdocumented12F19moNotdocumentedNotdocumentedNotdocumentedNormalNoneNotperformedornotdocumentedNotdocumentedADOS,autismdiagnosticobservationschedule;BayleyII,BayleyScalesofInfantDevelopment,secondedition;BayleyIII,Bayleyscalesofinfantandtoddlerdevelopment,thirdedition;CA,chronologicalageattesting;MR,mentalretardation;SB5,Stanford-Binetintelligencescales,fthedition;FSIQ,fullscaleIQ;VIQ,verbalIQ;NVIQ,nonverbalIQ;PIQ,performanceIQ;WPPSI-III,Wechslerpreschoolandprimaryscaleofintelligence,thirdedition;WISC-IV,Wechslerintelligencescaleforchildren,fourthedition;VCI,verbalcomprehensionindex,PRI,perceptualreasoningindex;WMI,workingmemoryindex;PSI,processingspeedindex;y,years;mo,months.
942AMERICANJOURNALOFMEDICALGENETICSPARTBTABLEIII.
RelevantPhysicalCharacteristicsSubjectDysmorphicfeaturesVertebral/skeletalCardiacSkin1NoneNotdocumentedNormalNotdocumented2FrontalbossingHistoryofplagiocephalyResolvedheartmurmurHemangiomaonneck3Epicanthalfolds;hypertelorismsmallerbifrontalregionProminentcoronalsutures,feet:higharchesandsomewhatsmalllengthNormalLighterthanparents4Down-slantingpalpebralssures;antevertednares;mildretrognathia,pointedchinNotdocumentedNormalNormal5NoneCurved2ndtoes,incompletefusionofringofrstcervicalvertebraNarrowedaorticarch,2VSDsNotdocumented6NoneBilateralhipdysplasiaProlongedQTc(457msec)Hemangiomaonneck7Slightlydeepseteyes,largeearsNormalNormalNormal8Longface,malarhypoplasia,prominenttubularnosewithpointednasaltip,hypoplasticalaenase,longatphiltrum,thinvermilion,prominentchin,longslenderngers,thintoesNotdocumentedNormalNormal9Lownasalbridge,smalljaw,verysmoothphiltrum.
Slightlyatmid-faceandprominentcheeksMildclinodactylyandunevendigitlengthsNormalNotdocumented10Dolichocephaly(32-weekprematureinfant)NotdocumentedNormalHemangiomaonback11NoneChest-rightmildPolandanomalyNormalEczema12Relativemacrocephaly(headcircumference90%),cuppingofleftear,frontalbossingOpenanteriorfontanelleat19monthsSmallmuscularVSD,fenestrationinatrialseptum,smallPDANotdocumentedVSD,ventricularseptaldefect;PDA,patentductusarteriosus;QTc,correctedQTinterval(normal<440msec).
CHINGETAL.
943hormone/choriogonadotropinreceptor(LHCGR),andStonedB-likefactor(STN1).
Toourknowledge,noneofthesegeneshasbeenassociatedwithseizuresormentalretardationintheliterature.
AlthoughwecannotbecertainthatthesefeaturesareadirectconsequenceofNRXN1deletion,ourobservationssuggestthatthephenotypiccharacteristicsofNRXN1deletionmaybewiderthanpreviouslyreported.
ThemutationswehaveobservedinourclinicalcohortareprimarilyinNRXN1-a.
Subjectswithsmalldeletions(under3-Mb)clusteredintotwogroups(Fig.
1).
Onegroup(subjects3–7)haddeletionsinvolvingpartoftheinitialLNSandEGFdomains-encodingregionsofNRXN1-a.
Oftheseveindividuals,threehadautismspectrumdisorders.
OneadditionalcasefromtheHMCAwasalsofoundtohaveadeletioninthisregion,whichissimilartothedeletioninsubject7fromtheclinicallyreferredcohort.
Asecondgroup(subjects8–12)haddeletionsthatclusteredaroundaregionfurtherfromtheapromotorofthegene(Fig.
1).
Allveofthesesubjects'deletionsencompassedanexonofanisoformwhosefunctionisnotwellunderstood.
Furthermore,whiletwosubjects(8and9)haddeletionsinvolvingotherexonsofNRXN1-aaswellasthisminorisoform,threesubjects'deletions(10–12)containonlytheexonofthisminorisoform.
ThisminorisoformisanEnsemblannotatedtranscript,namedENST00000406859(Fig.
1).
Itcontains13exonswith2,590bptranscriptionand856residuesoftranslationlength.
Thecodedprotein(ENSP00000385681)consistsofoneLNSandEGFdomain.
Itsfunctioniscurrentlyunknown.
Onesuchsubject(10)withadenovodeletioninthisregionhasbeendiagnosedwithPDD-NOS,suggestingpotentialclinicalrele-vanceforthisisoform.
Thisdeletioninintron5hasnottoourknowledgebeenpreviouslyreportedasbeingassociatedwithabnormaldevelopment.
Neurexin-1-bmutationswerelesscommon.
TwoofthesubjectsinourcohorthadlargedeletionsencompassingexonsforNRXN1-aand-b.
MissensevariantsinNRXN1-b(R8P,L13F,S14L,andT40S)havepreviouslybeenidentiedinindividualswithautism[Fengetal.
,2006;Kimetal.
,2008].
Relativesoftheseindividualswithautismwhosharedthesemissensemutationsdemonstratedsomedegreeoflearningorbehavioralissuesbutdidnotappeartomeetfullautismspectrumdisordercriteria[Fengetal.
,2006;Kimetal.
,2008].
Thisisconsistentwithourndingsofamixedphenotypeassociatedwithdeletionsinthisregionrangingfromautismspectrumdisorderstohypotoniawithcarrierrelativeswhoarenotasaffected.
InadditiontotheirNRXN1deletions,subjects8and11hadadditionalgenomicimbalancesasdescribedinTableI.
Thesegenomicimbalanceswereallinheritedfromunaffectedparents.
Thetwoduplicationson15q26.
3and17p11.
2insubject11overlapFIG.
2.
A:NRXN1-adeletionssegregatewithautismspectrumdisorder(ASD)andmildmentalretardation.
Pedigree1showsco-segregationofahemizygousCNVbetweenrs17041500andrs17512199whichdeletestherstthreecodingexons(DelEx1-3)ofNRXN1-a.
TheCNViscarriedbyallsubjectswithASDanddiminishedintelligencequotient(IQ),butnotbyatypicallydevelopingsibling.
Pedigree2showsco-segregationofahemizygousCNVwhichdeleteslikelyregulatory,genomicDNAupstream(Del50Reg)ofNRXN1-a.
PDD-NOS,pervasivedevelopmentdisorder,nototherwisespecied.
,wild-type,non-deletedDNA.
B:MappingofinferredCNdataSNP-by-SNPontheUCSCgenomebrowserdemonstratestheextentacrosstheNRXN1locus.
VerticalredlinesindicateeachSNPwithcopynumberof1or2.
Horizontalgreenlinesdemarcatetheextentofeachdeletion.
AlignmentofannotatedgenesintheRefSeqdatabaseareshownaswellasarepresentationofvertebrateconservationusingmultizandrelatedtoolsintheUCSC/PennStateBioinformaticscomparativegenomicalignmentpipeline.
Ofnote,Del50Regdeletesthelastfourexonsofanuncharacterized,splicedmRNAAK127244thatisexpressedinbrain.
ThegeneistranscribedintheoppositedirectionasNRXN1-ayetthetranscriptionstartsiteiswithin3.
5kbsuggestingthatthismRNAmaybetranscribedcoordinatelywithNRXN1-a.
[Colorgurecanbeviewedintheonlineissue,whichisavailableatwww.
interscience.
wiley.
com.
]944AMERICANJOURNALOFMEDICALGENETICSPARTBwithknownbenignCNVsandareunlikelycontributoryfactorstothepatient'scondition.
Theduplicationat5p13.
2insubject11anddeletionat3p24.
3insubject8arenotpreviouslyreportedCNVbutcontainnoknowngenesassociatedwithdevelopmentaldisorders,thusareconsideredasCNVofunknownsignicance.
Nevertheless,itisunclearwhethertheseCNVsmodiedtheobservedphenotype.
NRXN1andSynapseFunctionPriorstudieshavefunctionallylinkedothermoleculesthatareassociatedwithNRXN1toarangeofneuropsychiatricdisordersincludingautism.
Theseincludeneuroligins3and4(NLGN3,NLGN4)andSH3andmultipleankyrinrepeatdomains3(SHANK3)[Jamainetal.
,2002;Laumonnieretal.
,2004;Durandetal.
,2007;Moessneretal.
,2007;Lawson-Yuenetal.
,2008].
Inaddition,CNTNAP2(contactinassociatedprotein-like2)[Alarconetal.
,2008;Arkingetal.
,2008;Bakkalogluetal.
,2008]andcadherin10(CDH10)and9(CDH9)havebeenalsoassociatedwithautismspectrumdisorders[Wangetal.
,2009].
OurndingthatNRXN1isalsoassociatedwithautismanddevelopmentaldisordersaddsfurtherevidencetotheimportanceofthismolecularfamilytothedevelopmentofneurodevelopmentaldisorders.
ThefunctionofNRXN1infacilitatingsynaptictransmissionsuggeststhatmutationsinthisgenemaypredisposetoaneurologicdisconnectionsyndrome.
Long-rangedisconnectionsbetweenneuralnetworkshavebeenhypothesizedtobecausativeinsomepopulationswithautism[Barnea-Goralyetal.
,2004;Frith,2004;Justetal.
,2004;GeschwindandLevitt,2007].
TheeffectsofNRXN1onlanguagedevelopmentandhypotoniamaylikewiseberelatedtolong-rangeconnectivitywithinthebrain.
PhenotypicVariationPhenotypicvariationsmayreectthehighlypleiotropiceffectsobservedforspecicCNVssuchasthoseassociatedwithNRXN1.
Inaddition,anumberofoursubjectsinheritedNRXN1deletionsfromtheirparents.
Thedetailedphenotypeoftheseparentswerenotdescribedinthemedicalrecordsexceptinthefamilyhistory,buttheparentswereostensiblylessaffectedthantheirchildren.
ThissuggeststhatdeletionintheNRXN1genemaynotbefullypenetrant,orinteractswithothergenesresultinginthevariablephenotype.
Furtherresearcheffortstoinvestigatesuchvariablephenotypesassociatedwiththisunstablegenomicregionwillpro-videfurtherinsightintotheroleofNRXN1inthedevelopmentoflanguagedelays,autismspectrumdisorders,andphysicalfeatures.
LimitationsTheaccuracyandcompletenessoftheclinicalphenotypeidentiedinthisstudyisentirelydependentontheclinicalinformationthatwasdocumentedinthemedicalrecordsofthesesubjects,oftenbeforetheNRXN1deletionswereidentiedinthem.
Becauseoftheclinicalvariabilityexhibitedinourcohort,thesubjectswereseenbyavarietyofspecialists,whichaffectedthecompletenessofdata.
Inaddition,theparentswerenotformallyassessedtoascertaintheircognitive,physical,andbehavioralphenotypes.
Asnotedabove,reviewoffamilyhistorysuggeststhatsomeparentsmayhavesharedsimilarphenotypestotheirchildren.
Weareconduct-ingfurthertestingonboththesubjectsandtheirparentstobetterclarifydevelopmentaland/orsocialcognitionissuesinsubjectsandtheirparents.
ForthedeletionCNVsignicancetest,weusedthenormalcontroldatageneratedbydifferentgenomicprolingarrayplat-formsasreference.
Knowingthatthesensitivityandspecicitydifferfromonearrayplatformtoanother,thismaynotbeanoptimalcomparison.
However,theeffortwasmadetominimizethedetectionbiasbetweendifferentarrayplatforms.
Herewehaveonlychosenrecentstudiesusingarrayplatformofsimilarresolutionasours.
AllthesepublishedarticlesreportedthedetectionofsmallerCNV,suggestingthattechnicallyallthesearrayplatformswereabletodetectanyCNVidentiedinthisstudy.
Thusthiscomparison,althoughanapproximation,isontheconservativeside.
Finallyweacknowledgethatwhileourclinicallyascertainedsubjectswerenotdrawnfromacohortwithasinglediagnosissuchasautismorschizophrenia,theywereascertainedfromaheteroge-neouslyaffectedgroupinwhomgenetictestingwasconsideredclinicallyrelevant.
Asaresult,thereisascertainmentbiasandourndingsmaynotreectthetruedistributionofphysicalanddevelopmentalndingsintheNRXN1deletionphenotype.
Never-theless,wehavedemonstratedthatthereareanumberofotherphenotypicfeaturespresentinthisclinicalpopulationbeyondwhathaspreviouslybeenidentiedintheliterature.
CONCLUSIONWefoundawiderangeofphenotypicfeaturesinagroupofsubjectswithNRXN1deletionswhowereclinicallyreferredforgenetictesting.
Theseincludesubjectswithautismspectrumdisorders,mentalretardation,languagedelays,hypotonia,hemangiomas,andtheVACTERLassociation.
ACKNOWLEDGMENTSTheauthorsgratefullyacknowledgetheassistancebyourcolleaguesfromtheDNADiagnosticsLab:VaLip,XiaomingSheng,AnnReinhard,HongFang,SivTang,HongShao,HaitaoZhu,SamTang,andAndrewChengfortechnicalsupportofarrayCGH;ChristopherA.
WalshLab:DanielleGleasonandDanielRakiecfortechnicalsupportandRobertSeanHillforbioinformaticssupport.
WearefurthergratefulforthesupportfromtheNancyLurieMarksFamilyFoundation(C.
A.
W.
),theSimonsFoundation(C.
A.
W.
andJ.
F.
G.
),AutismSpeaks(J.
F.
G.
),andtheNIH(5K23MH080954-02toE.
M.
M.
and1R01MH083565toC.
A.
W).
E.
C.
E.
andC.
A.
W.
areInvestigatorsoftheHowardHughesMedicalInstitute.
Y.
S.
holdsaYoungInvestigatorAwardfromtheChildren'sTumorFoundationandCatalystAwardfromHarvardMedicalSchool,E.
M.
M.
holdsaCareerAwardforMedicalScientistsfromtheBurroughsWellcomeFund,B.
L.
W.
holdsaFudanScholarResearchAwardfromFudanUniversity.
REFERENCESAlarconM,AbrahamsBS,StoneJL,DuvallJA,PerederiyJV,BomarJM,SebatJ,WiglerM,MartinCL,LedbetterDH,etal.
2008.
Linkage,association,andgene-expressionanalysesidentifyCNTNAP2asanautism-susceptibilitygene.
AmJHumGenet82(1):150–159.
CHINGETAL.
945AracD,BoucardAA,OzkanE,StropP,NewellE,SudhofTC,BrungerAT.
2007.
Structuresofneuroligin-1andtheneuroligin-1/neurexin-1betacomplexrevealspecicprotein-proteinandprotein-Ca2interactions.
Neuron56(6):992–1003.
ArkingDE,CutlerDJ,BruneCW,TeslovichTM,WestK,IkedaM,ReaA,GuyM,LinS,CookEH,etal.
2008.
AcommongeneticvariantintheneurexinsuperfamilymemberCNTNAP2increasesfamilialriskofautism.
AmJHumGenet82(1):160–164.
BakkalogluB,O'RoakBJ,LouviA,GuptaAR,AbelsonJF,MorganTM,ChawarskaK,KlinA,Ercan-SencicekAG,StillmanAA,etal.
2008.
Molecularcytogeneticanalysisandresequencingofcontactinassociatedprotein-like2inautismspectrumdisorders.
AmJHumGenet82(1):165–173.
Barnea-GoralyN,KwonH,MenonV,EliezS,LotspeichL,ReissAL.
2004.
Whitematterstructureinautism:Preliminaryevidencefromdiffusiontensorimaging.
BiolPsychiatry55(3):323–326.
BierutLJ,MaddenPA,BreslauN,JohnsonEO,HatsukamiD,PomerleauOF,SwanGE,RutterJ,BertelsenS,FoxL,etal.
2007.
Novelgenesidentiedinahigh-densitygenomewideassociationstudyfornicotinedependence.
HumMolGenet16(1):24–35.
ChenX,LiuH,ShimAH,FociaPJ,HeX.
2008.
Structuralbasisforsynapticadhesionmediatedbyneuroligin-neurexininteractions.
NatStructMolBiol15(1):50–56.
ComolettiD,GrishaevA,WhittenAE,TsigelnyI,TaylorP,TrewhellaJ.
2007.
Synapticarrangementoftheneuroligin/beta-neurexincomplexrevealedbyX-rayandneutronscattering.
Structure15(6):693–705.
DudanovaI,SedejS,AhmadM,MasiusH,SargsyanV,ZhangW,RiedelD,AngensteinF,SchildD,RupnikM,etal.
2006.
Importantcontributionofalpha-neurexinstoCa2-triggeredexocytosisofsecretorygranules.
JNeurosci26(41):10599–10613.
DudanovaI,TabuchiK,RohlmannA,SudhofTC,MisslerM.
2007.
Dele-tionofalpha-neurexinsdoesnotcauseamajorimpairmentofaxonalpathndingorsynapseformation.
JCompNeurol502(2):261–274.
DurandCM,BetancurC,BoeckersTM,BockmannJ,ChasteP,FauchereauF,NygrenG,RastamM,GillbergIC,AnckarsaterH,etal.
2007.
Muta-tionsinthegeneencodingthesynapticscaffoldingproteinSHANK3areassociatedwithautismspectrumdisorders.
NatGenet39(1):25–27.
FengJ,SchroerR,YanJ,SongW,YangC,BockholtA,CookEH,SkinnerC,SchwartzCE,SommerSS.
2006.
Highfrequencyofneurexin1betasignalpeptidestructuralvariantsinpatientswithautism.
NeurosciLett409(1):10–13.
FrithC.
2004.
IsautismadisconnectiondisorderLancetNeurol3(10):577.
GeschwindDH,LevittP.
2007.
Autismspectrumdisorders:Developmentaldisconnectionsyndromes.
CurrOpinNeurobiol17(1):103–111.
GlessnerJT,WangK,CaiG,KorvatskaO,KimCE,WoodS,ZhangH,EstesA,BruneCW,BradeldJP,etal.
2009.
Autismgenome-widecopynumbervariationrevealsubiquitinandneuronalgenes.
Nature459(7246):569–573.
GrafER,ZhangX,JinSX,LinhoffMW,CraigAM.
2004.
NeurexinsinducedifferentiationofGABAandglutamatepostsynapticspecializationsvianeuroligins.
Cell119(7):1013–1026.
IchtchenkoK,HataY,NguyenT,UllrichB,MisslerM,MoomawC,SudhofTC.
1995.
Neuroligin1:Asplicesite-specicligandforbeta-neurexins.
Cell81(3):435–443.
IchtchenkoK,NguyenT,SudhofTC.
1996.
Structures,alternativesplicing,andneurexinbindingofmultipleneuroligins.
JBiolChem271(5):2676–2682.
InternationalSchizophreniaConsortium.
2008.
Rarechromosomaldele-tionsandduplicationsincreaseriskofschizophrenia.
Nature455(7210):237–241.
ItsaraA,CooperGM,BakerC,GirirajanS,LiJ,AbsherD,KraussRM,MyersRM,RidkerPM,ChasmanDI,etal.
2009.
Populationanalysisoflargecopynumbervariantsandhotspotsofhumangeneticdisease.
AmJHumGenet84(2):148–161.
JamainS,BetancurC,QuachH,PhilippeA,FellousM,GirosB,GillbergC,LeboyerM,BourgeronT,ParisAutismResearchInternationalSibpairS.
2002.
Linkageandassociationoftheglutamatereceptor6genewithautism.
MolPsychiatry7(3):302–310.
JustMA,CherkasskyVL,KellerTA,MinshewNJ.
2004.
Corticalactivationandsynchronizationduringsentencecomprehensioninhigh-function-ingautism:Evidenceofunderconnectivity.
Brain127(Pt8):1811–1821.
KentWJ,SugnetCW,FureyTS,RoskinKM,PringleTH,ZahlerAM,HausslerD.
2002.
ThehumangenomebrowseratUCSC.
GenomeRes12(6):996–1006.
KimHG,KishikawaS,HigginsAW,SeongIS,DonovanDJ,ShenY,LallyE,WeissLA,NajmJ,KutscheK,etal.
2008.
Disruptionofneurexin1associatedwithautismspectrumdisorder.
AmJHumGenet82(1):199–207.
KirovG,GumusD,ChenW,NortonN,GeorgievaL,SariM,O'DonovanMC,ErdoganF,OwenMJ,RopersHH,etal.
2008.
ComparativegenomehybridizationsuggestsaroleforNRXN1andAPBA2inschizophrenia.
HumMolGenet17(3):458–465.
LaumonnierF,Bonnet-BrilhaultF,GomotM,BlancR,DavidA,MoizardMP,RaynaudM,RonceN,LemonnierE,CalvasP,etal.
2004.
X-linkedmentalretardationandautismareassociatedwithamutationintheNLGN4gene,amemberoftheneuroliginfamily.
AmJHumGenet74(3):552–557.
Lawson-YuenA,SaldivarJS,SommerS,PickerJ.
2008.
FamilialdeletionwithinNLGN4associatedwithautismandTourettesyndrome.
EurJHumGenet16(5):614–618.
MarshallCR,NoorA,VincentJB,LionelAC,FeukL,SkaugJ,ShagoM,MoessnerR,PintoD,RenY,etal.
2008.
Structuralvariationofchro-mosomesinautismspectrumdisorder.
AmJHumGenet82(2):477–488.
MisslerM,SudhofTC.
1998.
Neurexins:Threegenesand1001products.
TrendsGenet14(1):20–26.
MisslerM,ZhangW,RohlmannA,KattenstrothG,HammerRE,Gott-mannK,SudhofTC.
2003.
Alpha-neurexinscoupleCa2channelstosynapticvesicleexocytosis.
Nature423(6943):939–948.
MoessnerR,MarshallCR,SutcliffeJS,SkaugJ,PintoD,VincentJ,ZwaigenbaumL,FernandezB,RobertsW,SzatmariP,etal.
2007.
ContributionofSHANK3mutationstoautismspectrumdisorder.
AmJHumGenet81(6):1289–1297.
MorrowEM,YooSY,FlavellSW,KimTK,LinY,HillRS,MukaddesNM,BalkhyS,GasconG,HashmiA,etal.
2008.
Identifyingautismlociandgenesbytracingrecentsharedancestry.
Science321(5886):218–223.
NagaseT,IshikawaK,MiyajimaN,TanakaA,KotaniH,NomuraN,OharaO.
1998.
Predictionofthecodingsequencesofunidentiedhumangenes.
IX.
Thecompletesequencesof100newcDNAclonesfrombrainwhichcancodeforlargeproteinsinvitro.
DNARes5(1):31–39.
NamCI,ChenL.
2005.
Postsynapticassemblyinducedbyneurexin-neuroligininteractionandneurotransmitter.
ProcNatlAcadSciUSA102(17):6137–6142.
NeedAC,GeD,WealeME,MaiaJ,FengS,HeinzenEL,ShiannaKV,YoonW,KasperaviciuteD,GennarelliM,etal.
2009.
Agenome-wideinvestigationofSNPsandCNVsinschizophrenia.
PLoSGenet5(2):e1000373.
NussbaumJ,XuQ,PayneTJ,MaJZ,HuangW,GelernterJ,LiMD.
2008.
Signicantassociationoftheneurexin-1gene(NRXN1)withnicotinedependenceinEuropean-andAfrican-Americansmokers.
HumMolGenet17(11):1569–1577.
946AMERICANJOURNALOFMEDICALGENETICSPARTBPuschelAW,BetzH.
1995.
Neurexinsaredifferentiallyexpressedintheembryonicnervoussystemofmice.
JNeurosci15(4):2849–2856.
RujescuD,IngasonA,CichonS,PietilainenOP,BarnesMR,ToulopoulouT,PicchioniM,VassosE,EttingerU,BramonE,etal.
2009.
Disruptionoftheneurexin1geneisassociatedwithschizophrenia.
HumMolGenet18(5):988–996.
SudhofTC.
2008.
Neuroliginsandneurexinslinksynapticfunctiontocognitivedisease.
Nature455(7215):903–911.
SugitaS,SaitoF,TangJ,SatzJ,CampbellK,SudhofTC.
2001.
Astoichiometriccomplexofneurexinsanddystroglycaninbrain.
JCellBiol154(2):435–445.
SzatmariP,PatersonAD,ZwaigenbaumL,RobertsW,BrianJ,LiuXQ,VincentJB,SkaugJL,ThompsonAP,SenmanL,etal.
2007.
Mappingautismrisklociusinggeneticlinkageandchromosomalrearrangements.
NatGenet39(3):319–328.
TabuchiK,SudhofTC.
2002.
Structureandevolutionofneurexingenes:Insightintothemechanismofalternativesplicing.
Genomics79(6):849–859.
UllrichB,UshkaryovYA,SudhofTC.
1995.
Cartographyofneurexins:Morethan1000isoformsgeneratedbyalternativesplicingandexpressedindistinctsubsetsofneurons.
Neuron14(3):497–507.
UshkaryovYA,PetrenkoAG,GeppertM,SudhofTC.
1992.
Neurexins:Synapticcellsurfaceproteinsrelatedtothealpha-latrotoxinreceptorandlaminin.
Science257(5066):50–56.
VrijenhoekT,Buizer-VoskampJE,vanderSteltI,StrengmanE,GeneticR,SabattiC,GeurtsvanKesselA,BrunnerHG,OphoffRA,etal.
2008.
OutcomeinPsychosisC.
RecurrentCNVsdisruptthreecandidategenesinschizophreniapatients.
AmJHumGenet83(4):504–510.
WalshT,McClellanJM,McCarthySE,AddingtonAM,PierceSB,CooperGM,NordAS,KusendaM,MalhotraD,BhandariA,etal.
2008.
Rarestructuralvariantsdisruptmultiplegenesinneurodevelopmentalpath-waysinschizophrenia.
Science320(5875):539–543.
WangK,ZhangH,MaD,BucanM,GlessnerJT,AbrahamsBS,SalyakinaD,ImielinskiM,BradeldJP,SleimanPM,etal.
2009.
Commongeneticvariantson5p14.
1associatewithautismspectrumdisorders.
Nature459(7246):528–533.
YanJ,NoltnerK,FengJ,LiW,SchroerR,SkinnerC,ZengW,SchwartzCE,SommerSS.
2008.
Neurexin1alphastructuralvariantsassociatedwithautism.
NeurosciLett438(3):368–370.
ZahirFR,BarossA,DelaneyAD,EydouxP,FernandesND,PughT,MarraMA,FriedmanJM.
2008.
Apatientwithvertebral,cognitiveandbehav-iouralabnormalitiesandadenovodeletionofNRXN1alpha.
JMedGenet45(4):239–243.
ZengZ,SharpeCR,SimonsJP,GoreckiDC.
2006.
Theexpressionandalternativesplicingofalpha-neurexinsduringXenopusdevelopment.
IntJDevBiol50(1):39–46.
ZhangW,RohlmannA,SargsyanV,AramuniG,HammerRE,SudhofTC,MisslerM.
2005.
Extracellulardomainsofalpha-neurexinsparticipateinregulatingsynaptictransmissionbyselectivelyaffectingN-andP/Q-typeCa2channels.
JNeurosci25(17):4330–4342.
CHINGETAL.
947
L.
Ching,1,2YipingShen,2,3,7Wen-HannTan,2,4ShafaliS.
Jeste,2,5EricM.
Morrow,6XiaoliChen,7,8NahitM.
Mukaddes,9Seung-YunYoo,4EllenHanson,1,2RachelHundley,1,2ChristinaAustin,4RonaldE.
Becker,1,2GerardT.
Berry,2,4KatherineDriscoll,1,2ElizabethC.
Engle,2,5,10,11,12SandraFriedman,1,2JamesF.
Gusella,2,3,13FukiM.
Hisama,2,4MiraB.
Irons,2,4TinaLaosca,1,2ElaineLeClair,1,2DavidT.
Miller,2,4,7MichaelNeessen,1,2JonathanD.
Picker,2,4LeonardRappaport,1,2CynthiaM.
Rooney,2,5DeanP.
Sarco,2,5JoanM.
Stoler,2,4ChristopherA.
Walsh,2,4,11,14RobertR.
Wolff,2,5TingZhang,8RamziH.
Nasir,1,2*Bai-LinWu2,7,15**onbehalfoftheChildren'sHospitalBostonGenotypePhenotypeStudyGroup1DivisionofDevelopmentalMedicine,Children'sHospitalBoston,Boston,Massachusetts2HarvardMedicalSchool,Boston,Massachusetts3CenterforHumanGeneticResearch,MassachusettsGeneralHospital,Boston,Massachusetts4DivisionofGenetics,Children'sHospitalBoston,Boston,Massachusetts5DepartmentofNeurology,Children'sHospitalBoston,Boston,Massachusetts6DepartmentofMolecularBiology,CellBiologyandBiochemistry,BrownUniversity,Providence,RhodeIsland7DepartmentofLaboratoryMedicine,Children'sHospitalBoston,Boston,Massachusetts8DepartmentofMolecularImmunology,CapitalInstituteofPediatrics,Beijing,China9IstanbulFacultyofMedicine,DepartmentofChildPsychiatry,IstanbulUniversity,Istanbul,Turkey10Children'sHospitalBoston,HowardHughesMedicalInstitute,Boston,Massachusetts11MantonCenterforOrphanDiseaseResearch,Children'sHospitalBoston,Boston,Massachusetts12DepartmentofOphthalmology,Children'sHospitalBoston,Boston,Massachusetts13DepartmentofGenetics,HarvardMedicalSchool,Boston,Massachusetts14HowardHughesMedicalInstitute,BethIsraelDeaconessMedicalCenter,Boston,Massachusetts15Children'sHospitalandInstitutesofBiomedicalScience,FudanUniversity,Shanghai,ChinaReceived1July2009;Accepted15December2009AdditionalSupportingInformationmaybefoundintheonlineversionofthisarticle.
TheChildren'sHospitalBostonGenotypePhenotypeStudyGroupalsoincludesOmarS.
Khwaja,AnnapurnaPoduri,MustafaSahinandMagdiSobeih,DepartmentofNeurology,Children'sHospitalBoston,HarvardMedicalSchool,Boston,Massachusetts.
Grantsponsors:NancyLurieMarksFamilyFoundation;SimonsFoundation;AutismSpeaks;NIH;Grantnumbers:5K23MH080954-02,1R01MH083565.
M.
S.
L.
ChingandY.
Shencontributedequallytothiswork.
*Correspondenceto:RamziH.
Nasir,DivisionofDevelopmentalMedicine,Children'sHospitalBoston,HarvardMedicalSchool.
300LongwoodAve.
,Boston,MA02115.
E-mail:ramzi.
nasir@childrens.
harvard.
edu**Correspondenceto:Bai-LinWu,DepartmentsofLaboratoryMedicineandPathology,Children'sHospitalBoston,HarvardMedicalSchool.
300LongwoodAve.
,Boston,MA02115.
E-mail:bai-lin.
wu@childrens.
harvard.
eduPublishedonline7April2010inWileyInterScience(www.
interscience.
wiley.
com)DOI10.
1002/ajmg.
b.
310632010Wiley-Liss,Inc.
937NeuropsychiatricGeneticsResearchhasimplicatedmutationsinthegeneforneurexin-1(NRXN1)inavarietyofconditionsincludingautism,schizo-phrenia,andnicotinedependence.
Toourknowledge,therehavebeennopublishedreportsdescribingthebreadthofthepheno-typeassociatedwithmutationsinNRXN1.
WepresentamedicalrecordreviewofsubjectswithdeletionsinvolvingexonicsequencesofNRXN1.
Weascertainedcasesfrom3,540individ-ualsreferredclinicallyforcomparativegenomichybridizationtestingfromMarch2007toJanuary2009.
Twelvesubjectswereidentiedwithexonicdeletions.
ThephenotypeofindividualswithNRXN1deletionisvariableandincludesautismspectrumdisorders,mentalretardation,languagedelays,andhypotonia.
TherewasastatisticallysignicantincreaseinNRXN1deletioninourclinicalsamplecomparedtocontrolpopulationsdescribedintheliterature(P8.
9107).
ThreeadditionalsubjectswithNRXN1deletionsandautismwereidentiedthroughtheHomozygosityMappingCollaborativeforAutism,andthisdeletionsegregatedwiththephenotype.
OurstudyindicatesthatdeletionsofNRXN1predisposetoawidespectrumofdevelopmentaldisorders.
2010Wiley-Liss,Inc.
Keywords:NRXN1(neurexin-1);developmentaldisorders;arrayCGH;NRXN1exonicdeletions;CNVINTRODUCTIONNeurexinsareagroupofhighlypolymorphiccellsurfaceproteinsinvolvedinsynapseformationandsignaling[Ushkaryovetal.
,1992;MisslerandSudhof,1998;Missleretal.
,2003;Grafetal.
,2004;NamandChen,2005].
Therearethreehumanneurexingenes(NRXN1,NRXN2,andNRXN3),eachofwhichhastwoindepen-dentpromotersresultinginanaandabneurexinforeachgene[Ushkaryovetal.
,1992;Ichtchenkoetal.
,1996].
Multiplealterna-tivesplicingleadstothepossibilityofgreaterthanathousanddistinctneurexinisoforms[Ullrichetal.
,1995].
Theirexpressionisbelievedtobespatiallyandtemporallyregulatedthroughoutdevelopment[PuschelandBetz,1995;Zengetal.
,2006].
StructureandFunctionofNRXN1NRXN1,locatedonchromosome2p16.
3,isoneofthelargestknownhumangenes(1.
1Mbwith24exons)[TabuchiandSudhof,2002].
Itissubjecttorelativelyfrequentdisruptionincludingmissensechanges,translocation,wholegenedeletion,andintra-geniccopynumberalterations[Fengetal.
,2006;Szatmarietal.
,2007;InternationalSchizophreniaConsortium,2008;Kimetal.
,2008;Kirovetal.
,2008;Marshalletal.
,2008;Morrowetal.
,2008;Yanetal.
,2008;Zahiretal.
,2008;Glessneretal.
,2009;Rujescuetal.
,2009].
Thelongertranscript,NRXN1-a,encodesanN-terminalsignalpeptidewiththreerepeatsoftwolaminin/neurexin/sexhormone-bindingglobulin(LNS)domainsseparatedbyanEGF-likesequence(Fig.
1).
Followingtheserepeats,thereisanO-glycosyla-tionsequence,atransmembranedomain,andacytoplasmictailof55aminoacids.
Neurexin-1-ahasbeenshowntointeractwithcertainneuroliginisoformsandneurexin-bindingproteinsknownasneurexophilins.
Thispresynapticmoleculeisalsorequiredforcalcium-triggeredneurotransmitterreleaseandthefunctionofvoltage-gatedcalciumchannelsinthesynapsesofthebrainstemandneocortex[Missleretal.
,2003;Zhangetal.
,2005;Dudanovaetal.
,2006].
Mouseknockoutsofallthreea-neurexingenesdonotdemonstratemajorabnormalitiesofaxonalpathndingduringdevelopment[Dudanovaetal.
,2007],althoughsynapticfunctionisseverelyimpaired.
Micewithknockoutsofindividuala-neurexingeneshavemodestlydecreasedpostnatalviability,whiledoubleknockoutmicehavegreatlydecreasedpostnatalsurvival.
Tripleknockoutmicedonotsurvivepasttherstdayoflife[Missleretal.
,2003].
Neurexin-1-bismuchshorterthanNeurexin-1-a,asveofthesixLNSdomainsandtheinterveningEGFsequencesarereplacedwithashortb-neurexin-specicsequence(Fig.
1)[MisslerandSudhof,1998].
Neurexin-1-bhasbeenshowntointeractwiththepostsynapticneuroliginfamilyofcelladhesionmoleculesanddystroglycans[Ichtchenkoetal.
,1995;Sugitaetal.
,2001;Aracetal.
,2007;Comolettietal.
,2007;Chenetal.
,2008].
NomousemodelswithknockoutsofNRXN1-b,aloneorincombinationwithNRXN1-a,haveyetbeenanalyzed[Sudhof,2008].
ForeachofNeurexin-1-aandNeurexin-1-b,multipleproteincodingisoformsofNRXN1havebeenidentied,whosestructureandfunctionsarenotwellunderstood.
NRXN1MutationsinHumansThereisincreasingevidencethatNRXN1disruptions[Kimetal.
,2008],pointmutations[Fengetal.
,2006;Yanetal.
,2008],anddeletions[Glessneretal.
,2009;Marshalletal.
,2008;Morrowetal.
,2008;Szatmarietal.
,2007]areassociatedwithautismspectrumdisorders.
NRXN1hasalsobeenfoundtobeassociatedwithautisminalargegenome-widesinglenucleotidepolymorphismassocia-tionstudy[Wangetal.
,2009].
NRXN1deletionshavealsobeenassociatedwithavarietyofotherconditionsincludingschizophrenia[InternationalSchizophreniaConsortium,2008;Kirovetal.
,2008;Vrijenhoeketal.
,2008;Walshetal.
,2008;Needetal.
,2009;Rujescuetal.
,2009],nicotinedependence[Bierutetal.
,2007;Nussbaumetal.
,2008],HowtoCitethisArticle:ChingMSL,ShenY,TanW-H,JesteSS,MorrowEM,ChenX,MukaddessNM,YooS-Y,HansonE,HundleyR,AustinC,BeckerRE,BerryGT,DriscollK,EngleEC,FriedmanS,GusellaJF,HisamaFM,IronsMB,LaoscaT,LeClairE,MillerDT,NeessenM,PickerJD,RappaportL,RooneyCM,SarcoDP,StolerJM,WalshCA,WolffRR,ZhangT,NasirRH,WuB-L,onbehalfoftheChildren'sHospitalBostonGenotypePhenotypeStudyGroup.
2010.
DeletionsofNRXN1(Neurexin-1)PredisposetoaWideSpectrumofDevelopmentalDisorders.
AmJMedGenetPartB153B:937–947.
938AMERICANJOURNALOFMEDICALGENETICSPARTBandotherphysicalmanifestationssuchasvertebralanomalies[Zahiretal.
,2008].
PriorreportsofabnormalitiesinNRXN1havefocusedonpopulationswithspecicdiagnoses(e.
g.
,autism,schizophrenia).
However,theclinicalsignicanceofcopynumbervariants(CNV),suchasdeletioninvolvingoneormoreexonsofNRXN1,andtherangeofphenotypicmanifestationsofsubjectswithNRXN1dele-tionCNVremainsunclear.
WedescribehereagroupofsubjectswithNRXN1deletionswhodemonstrateawiderangeofphysicalanddevelopmentalphenotypes.
MATERIALSANDMETHODSClinicalCohortRecordReviewFromMarch2007toJanuary2009,atotalof3,540subjectsatChildren'sHospitalBostonwereevaluatedforgenomicimbalance(deletionandduplication)usingtheAgilent244Khumangenomeoligonucleotidecomparativegenomichybridization(CGH)mi-croarrays(G4411B,AgilentTechnologies,PaloAlto,CA)accordingtothemanufacturer'sinstructions[OligonucleotideArray-BasedCGHforGenomicDNAAnalysisprotocolversion3(AgilentTechnologies)].
Themajorityofthereferralswereforclinicalfeaturesofdevelopmentaldisorders(developmentaldelay,autismspectrumdisorders,mentalretardation)ormultiplecongenitalmalformationsasdeterminedbyspecialistsinClinicalGenetics,Neurology,andDevelopmentalMedicine.
Onehundredthirtyprobescoverthe1.
12MbregionoftheNRXN1geneontheAgilent244KCGHarray.
Theaverageinterp-robespacewithintheNRXN1geneis8.
6kb.
Thispermitsthereliabledetectionofsmallintragenicdeletionsdownto43kbinsize.
ImageswerecapturedbyAgilentscannerandquantiedusingFeatureExtractionsoftwarev9.
0(AgilentTechnologies).
CGHAnalyticsSoftwarev3.
4(AgilentTechnologies)wassubsequentlyusedfordatanormalization,qualityevaluationanddatavisualiza-tion.
CopynumberaberrationwasindicatedusingtheAberrationDetectionMethod2(ADM-2)algorithm.
DeletionsinvolvingveormoreconsecutiveprobeswereconsideredastrueCNV.
Fortwolargerdeletions,uorescentinsituhybridization(FISH)testingusingprobeRP11-800C7wascarriedoutfordeletionconrmationandparentaltesting.
ThesmallerdeletionswereconrmedbyPCR-basedbreakpointmappingmethods.
Thepri-mersusedforeachcasearelistedintheSupplementaryMaterial.
SubjectswithdeletionsinvolvingexonicsequenceofNRXN1wereincludedinourreview.
Twodevelopmentalbehavioralpedia-tricians(RHN,MSLC),aclinicalgeneticist(WHT),andapediatricneurologist(SSJ)reviewedeachofthemedicalrecords.
Theclinicalhistory,physicalexamination,laboratorydata,andradiologicalreportsofeachsubjectwerereviewed.
AdditionalReportofCasesWithNRXN1DeletionandAutismCaseswithexonicandintragenicNRXN1deletionswerealsocontributedfromtheHomozygosityMappingCollaborativeforAutism(HMCA)whichutilizedtheAffymetrixGeneChipHumanMapping500KArraySetusingCNVdetectionmethodspreviouslydescribed[Morrowetal.
,2008].
ThisworkwasapprovedbytheInstitutionalReviewBoardsatthecorrespondinghospitals.
RESULTSClinicalCohortRecordReviewWeidentied12subjectsthroughChildren'sHospitalBostonwithdeletionsinvolvingexonicsequencesofNRXN1(TableIandFig.
1).
Thedeletionsreportedhererangefrom65kbto5Mbandmostofthesecasesarepredictedtoaffecttheinitialstructuraldomainsoftheprotein(Fig.
1).
FIG.
1.
Illustratesthesizeandrangeofthe12deletionCNVsinrelationtotheexonsandproteindomainsofNRXN1-aand-bintheUCSCGenomeBrowser(http://genome.
ucsc.
edu)[Kentetal.
,2002].
Thetoptrackshowsthegenomicpositionandsizeofthe12deletionCNVs.
ThemiddletracksshowthegeneannotationsinRefSeqandEnsembl.
TheRefseqGenesshowtheaandbisoformsoftheNRXN1gene;theEnsemblgenepredictionshowsseveralotherminorisoformsoftheNRXN1gene.
ThebottompanelshowstheproteindomainsoftheNRXN1-ageneproduct.
SP,signalpeptide;LNS,laminin/neurexin/sexhormone-bindingglobulindomain;EGF,epitheliumgrowthfactorlikedomain;OS,O-glycosylationsequence;TM,transmembranedomain;CT,cytoplasmictail.
tail.
[Colorgurecanbeviewedintheonlineissue,whichisavailableatwww.
interscience.
wiley.
com.
]CHINGETAL.
939TABLEI.
DeletionsWithinNRXN1inOurSamplePatientDeletionlocation(hg18build)Sizeofdeletion(kb)InheritanceExons–intronsdeletedOthergenetictestsandresults(additionalimbalance)IndicationfortestingConrmationmethod146,938,685–52,015,8855,077MaternalFISHnormal;paternalstudyunavailableAllKaryotypingandFragileXtest:normal(contiguousdeletionincludingFSHR,LHCGR,STN1)ModeratementalretardationFISH250,128,256–54,050,7133,923DenovoAllexceptthelasttwoexonsNoneGlobaldevelopmentaldelays,suspectedautismFISH350,897,002–51,212,385315PaternalExon1–5;partialintron5Karyotypingandchromosome15methylation:normalGrossmotordelay,hypotoniaPCR450,936,914–51,167,934231PaternalExon1–5;partialintron5Karyotyping,fragileXtest,SALL1,andCHD7mutationtest:normalPDD-NOS,hypotoniaPCR550,920,082–51,059,469139DenovoExon3,4,5;partialintrons2,5NoneVACTERLNotdone651,059,410–51,316,396257MaternalExon1,2;partialintron2KaryotypingandfragileXtest:normalPDD-NOS,motorcoordinationdelaysPCR751,090,504–51,212,385122PaternalExon1–3;partialintron3Karyotyping,FragileXtest,andPTENmutationtest:normalAutism,moderatementalretardationPCR850,522,892–50,827,767305DenovoExon6–17;partialintrons5,17aFragileXtest:normal(deletionat3p24.
3from21492764to21806824,maternallyinherited)MildmentalretardationPCR950,689,280–50,853,329164Unknown(fosterfamily)Exon6–8;partialintrons5,8aKaryotyping:normalLanguagedelay,prenatalsubstanceexposurePCR1050,714,297–50,853,329139DenovoIntron5aKaryotypingandfragileXtest:normalPDD-NOSPCR1150,735,499–50,811,01876MaternalIntron5aKaryotyping,PTEN,andNSD1mutationtests:normal(duplicationsat5p13.
2from37241141to37758854,paternallyinherited;at15q26.
3from98059710to98842423,maternallyinherited;at17p11.
2from21147675to21442522maternallyinherited)Hypotonia,muscleweakness,largebirthweightPCR1250,735,499–50,801,23366MaternalIntron5aNonePoorweightgain,mildcraniofacialdysmorphismPCRFSHR,follicle-stimulatinghormonereceptor;LHCGR,luteinizinghormone/choriogonadotropinreceptor;STN1,StonedB-likefactor;PDD-NOS,pervasivedevelopmentaldisorder,nototherwisespecied;VACTERL,vertebralanomalies,analatresia,cardiacmalformations,tracheoesophagealstula,renalanomalies,andlimbanomalies;SALL1,sal-like1(Drosophila);CHD7,chromodomainhelicaseDNA-bindingprotein7;PTEN,phosphataseandtensinhomolog;NSD1,nuclearreceptor-bindingSETdomainprotein1.
aDeletionsofintron5inthesepatientsinvolveanexonofaminorisoformofNRXN1.
940AMERICANJOURNALOFMEDICALGENETICSPARTBOfthese12deletions,4weredenovoCNVnotidentiedineitherparent,3werematernallyinherited,3werepaternallyinherited,andtheparentalsamplesfor1(subject9)werenotavailable.
Insubjects1,paternalsampleswerenotavailablebutthedeletionwasnotidentiedinmaternaltesting.
Insubjects1–9,thedeletionsinvolvedatleasttwoexonsofNRXN1-a,whileinsubjects10–12,thedeletionsinvolvedonlyanexonofaminorexpressedNRXN1isoform.
Thegenomicimbal-ancesinvolvingNRXN1aresummarizedinTableIandtheclinicalmanifestationsaresummarizedinTablesIIandIII.
FurtherclinicaldataareavailableintheSupplementaryMaterial.
Detailedclinicalrecordswereavailablefromgeneticistsin9outof12subjects,developmental-behavioralpediatriciansin6/12,psychologistsin6/12,andneurologistsin4/12.
Fourofthe12subjects(4,6,7,and10)werediagnosedwithautismspectrumdisorders;ineachpositivecase,thisdiagnosiswassupportedbytheAutismDiagnosticObservationSchedule.
Anothersubject(2)wassuspectedofhavingautismbuttheevaluationwasnotavailableforreview;healsohadglobaldevelopmentaldelays.
Twosubjectshadmentalretardationwithoutadiagnosisofanautismspectrumdisorder(1and8).
Subject1,inaddition,hadabsenceseizuresandanEEGconsistentwithaprimarygeneralizedepilepsy.
Onesubject(3)wastooyoungtoascertainforanautismspectrumdisorderorcognitivedelays.
Ninesubjectshadclinicaldocumentationofexpressiveorreceptivelanguagedelays.
Milddysmorphicfeatureswerepresentinsevensubjects(2,3,4,7,8,9,and12);threesubjectshadhemangiomas(2,6,and10).
Hypotoniawaspresentinfoursubjects(3,4,9,and11).
Twosubjects(5and12)hadventricularseptaldefects.
MedicalrecordreviewalsorevealedthefollowingcharacteristicsinthesixparentsfromwhomtheNRXN1deletionwasinherited.
Subject4,whohadpervasivedevelopmentaldisorder,notother-wisespecied(PDD-NOS)andhypotonia,inheritedhisdeletionfromhisfatherwhoisalsoreportedtobesociallyawkward.
Subject6,whohadPDD-NOSandcoordinationissues,inheritedthedeletionfromamotherwithahistoryoflanguagedelayandsocialskilldifculties.
Subject11,whohashypotonia,weakness,andPolandanomaly,inheritedthedeletionfromamotherwhohasahistoryofjointhypermobility,osteoarthritis,mitralvalveprolapse,severemigraines,andseverebreastasymmetry.
Thefatherofsubject3(hypotonia,grossmotordelay),thefatherofsubject7(autism,mentalretardation)andthemotherofsubject12(poorweightgain,craniofacialdysmorphism)arereportedtobehealthywithoutdevelopmentalormedicalconcerns.
AdditionalReportofCasesWithNRXN1DeletionandAutismInadditiontotheChildren'sHospitalBostoncases,wereportherethreecasesfromtwofamiliesascertainedthroughtheHMCA[Morrowetal.
,2008].
TheNRXN1deletionsineachwerediscov-eredtosegregatewithIQbelow70inthesepedigrees(Fig.
2).
Allthreeaffectedchildrenwerecarriersandunaffectedchildrenwerenot.
ThedeletionswereinheritedfromfatherswhowerefoundtohaveASDsymptomsandIQbetween60and70,whilenon-carriermotherswerenotontheautismspectrumandwithIQsinthenormalrange.
Thedeletionforthesubjectintherstfamilyisexonicandintragenic,whilethedeletionforthetwosiblingsinthesecondfamilyisupstreamandmayaffectgeneexpression.
Furtherinvestigationisnecessarytosubstantiatethisasafunctionaldele-tion,eventhoughitsegregateswithdisease.
SignicanceTestToestablishtherelevanceoftheseCNV,wecomparedthefrequencyofdeletionsinvolvingNRXN1-aexonsinourChildren'sHospitalBostonpopulation,inwhomCGHtestingwasconsideredtobeclinicallyindicated,tothefrequencyofsimilardeletionsdetectedbyarraygenomicprolingofequivalentresolutioninnormalpop-ulations.
Itsaraetal.
[2009]detectedthreedeletionsinvolvingNRXN1-aexonsin2,493normalindividuals.
TheInternationalSchizophreniaConsortium[2008]reportedtwoexonicdeletioncasesin3,181normalcontrols.
Anotherlarge-scaleschizophreniastudyidentiedvedeletioncasesamong33,746normalcontrols[Rujescuetal.
,2009].
Recently,Glessneretal.
[2009]reportednodeletionCNVinvolvingNRXN1-aamong1,409AutismCase–Control(ACC)controlsamplesand1,110AutismGeneticResourceExchange(AGRE)controls.
Collectively,thefrequencyofexonicdeletionofNRXN1-aincontrolpopulationsis10/51,939(0.
019%);thisdifferssignicantlyfromthefrequencyofexonicdeletionCNVweobservedinourclinicallyreferredpopulation(9/3,540)(0.
25%;P8.
9107,two-tailedFisher'sexacttest).
Therearenoavailabledataonthefrequencyofminorisoformexonicdeletionsincontrolpopulationsandthusthesesubjects(n3)wereexcludedfromthesignicancetest.
DISCUSSIONTherecentrecognitionofgenomicimbalanceinmanychromo-somalregionsthatareassociatedwithautism,mentalretardation,andschizophreniaisduetotheincreasinguseofwholegenomehigh-resolutionarrayCGHintheevaluationofindividualswiththesedisorders.
OurclinicalsubjectswithNRXN1deletionwereascertainedthroughapatientpopulationpresentingwithabroadrangeofreferringdiagnoses.
Throughacarefulreviewofmedicalrecords,weidentiedinoursubjectsanumberofclinicalfeaturesthathadnotbeenpreviouslyassociatedwithNRXN1deletions.
Theseincludelanguagedelays,mentalretardationwithoutautism,hypotonia,andhemangiomas.
Inaddition,twoofoursubjects(5and12)hadventricularseptaldefects.
Interestingly,thehumancDNAhomologoustoratNRXN1-ahasbeenisolatedinbothbrainandhearttissuessuggest-ingapotentialroleforNeurexin-1inbothbrainandheartdevel-opment[Nagaseetal.
,1998].
Oneofthesesubjects(5)alsohadevidenceofmultiplecongenitalanomaliesincludingvertebralanomaliesintheformofaVACTERLassociation.
Vertebralanomalieshavealsobeenreportedinoneothercaseintheliterature[Zahiretal.
,2008].
Apreviousreportshowedthepresenceofaseizuredisorderintwounrelatedindividualssharingthesamemissensevariantinexon1ofNRXN1-b[Fengetal.
,2006].
Inourcohort,onlyonesubjecthadaseizuredisorder(subject1),althoughhis5MbdeletionencompassedtheentireNRXN1geneaswellasthegenesforfollicle-stimulatinghormonereceptor(FSHR),luteinizingCHINGETAL.
941TABLEII.
NeurologicalandDevelopmentalCharacteristicsSubjectSexAgeatascertainmentAutismspectrumdisorderCognitive-developmentalndingsLanguagedelayMotorinvolvementHistoryofseizures/EEGresultsMRI-brainBehavioralfeatures1M16yNoMR;SB5:FSIQ44;VIQ44;NVIQ48;(CA14y)ExpressiveandreceptiveWalkedat18monthsHistoryofseizures;abnormalEEGNormalInattention,impulsivity,hyperactivity2M2yAutismsuspected,noformalevaluationavailableGlobaldevelopmentaldelaysExpressiveandreceptiveNotdocumentedNotdocumentedNotperformedornotdocumentedNotdocumented3F10moNotsuspectedNoconcernsreported.
TestingnotdocumentedNoMildgrossmotordelay,hypotoniaNoneNotperformedornotdocumentedNotdocumented4M4yPDD-NOS(ADOS)WPPSI-IIIVIQ77,PIQ98(CA4y)ExpressiveHypotoniaEEGNormalNotperformedornotdocumentedAttentionconcerns5F6yNoNoconcernsreported.
Testingnotdocumented6monthreceptivedelayNormalNotdocumentedNotperformedornotdocumentedNotdocumented6F7yPDD-NOS(ADOS)BayleyIImentalscale91,29mo(CA31mo)ExpressiveMotorcoordinationdisorderNoneNotperformedornotdocumentedNotdocumented7M14yAutism(ADOS)MR:SB5:FSIQ47;VIQ46;NVIQ53ExpressiveandreceptiveNormalEEGnormalNotperformedornotdocumentedHyperactivity8F11yNoMR:WISC-IV:VCI67,PRI63,WMI59,PSI75,FSIQ58(CA11y)ExpressiveandreceptiveNormalNoneNormalInattention,dgety,disorganized9F4yNoAcademicdelaysreported.
TestingnotdocumentedExpressiveandreceptiveHypotoniaNoneNormalImpulsivityandinattention10M2yPDD-NOS(ADOS)BayleyIIIcognitivescore95(average)ExpressiveandreceptiveNormalNotdocumentedNotperformedornotdocumentedNotdocumented11M8yNoNoconcernsreported.
TestingnotdocumentedNoProximalanddistalweakness,hypotoniaNoneNotperformedornotdocumentedNotdocumented12F19moNotdocumentedNotdocumentedNotdocumentedNormalNoneNotperformedornotdocumentedNotdocumentedADOS,autismdiagnosticobservationschedule;BayleyII,BayleyScalesofInfantDevelopment,secondedition;BayleyIII,Bayleyscalesofinfantandtoddlerdevelopment,thirdedition;CA,chronologicalageattesting;MR,mentalretardation;SB5,Stanford-Binetintelligencescales,fthedition;FSIQ,fullscaleIQ;VIQ,verbalIQ;NVIQ,nonverbalIQ;PIQ,performanceIQ;WPPSI-III,Wechslerpreschoolandprimaryscaleofintelligence,thirdedition;WISC-IV,Wechslerintelligencescaleforchildren,fourthedition;VCI,verbalcomprehensionindex,PRI,perceptualreasoningindex;WMI,workingmemoryindex;PSI,processingspeedindex;y,years;mo,months.
942AMERICANJOURNALOFMEDICALGENETICSPARTBTABLEIII.
RelevantPhysicalCharacteristicsSubjectDysmorphicfeaturesVertebral/skeletalCardiacSkin1NoneNotdocumentedNormalNotdocumented2FrontalbossingHistoryofplagiocephalyResolvedheartmurmurHemangiomaonneck3Epicanthalfolds;hypertelorismsmallerbifrontalregionProminentcoronalsutures,feet:higharchesandsomewhatsmalllengthNormalLighterthanparents4Down-slantingpalpebralssures;antevertednares;mildretrognathia,pointedchinNotdocumentedNormalNormal5NoneCurved2ndtoes,incompletefusionofringofrstcervicalvertebraNarrowedaorticarch,2VSDsNotdocumented6NoneBilateralhipdysplasiaProlongedQTc(457msec)Hemangiomaonneck7Slightlydeepseteyes,largeearsNormalNormalNormal8Longface,malarhypoplasia,prominenttubularnosewithpointednasaltip,hypoplasticalaenase,longatphiltrum,thinvermilion,prominentchin,longslenderngers,thintoesNotdocumentedNormalNormal9Lownasalbridge,smalljaw,verysmoothphiltrum.
Slightlyatmid-faceandprominentcheeksMildclinodactylyandunevendigitlengthsNormalNotdocumented10Dolichocephaly(32-weekprematureinfant)NotdocumentedNormalHemangiomaonback11NoneChest-rightmildPolandanomalyNormalEczema12Relativemacrocephaly(headcircumference90%),cuppingofleftear,frontalbossingOpenanteriorfontanelleat19monthsSmallmuscularVSD,fenestrationinatrialseptum,smallPDANotdocumentedVSD,ventricularseptaldefect;PDA,patentductusarteriosus;QTc,correctedQTinterval(normal<440msec).
CHINGETAL.
943hormone/choriogonadotropinreceptor(LHCGR),andStonedB-likefactor(STN1).
Toourknowledge,noneofthesegeneshasbeenassociatedwithseizuresormentalretardationintheliterature.
AlthoughwecannotbecertainthatthesefeaturesareadirectconsequenceofNRXN1deletion,ourobservationssuggestthatthephenotypiccharacteristicsofNRXN1deletionmaybewiderthanpreviouslyreported.
ThemutationswehaveobservedinourclinicalcohortareprimarilyinNRXN1-a.
Subjectswithsmalldeletions(under3-Mb)clusteredintotwogroups(Fig.
1).
Onegroup(subjects3–7)haddeletionsinvolvingpartoftheinitialLNSandEGFdomains-encodingregionsofNRXN1-a.
Oftheseveindividuals,threehadautismspectrumdisorders.
OneadditionalcasefromtheHMCAwasalsofoundtohaveadeletioninthisregion,whichissimilartothedeletioninsubject7fromtheclinicallyreferredcohort.
Asecondgroup(subjects8–12)haddeletionsthatclusteredaroundaregionfurtherfromtheapromotorofthegene(Fig.
1).
Allveofthesesubjects'deletionsencompassedanexonofanisoformwhosefunctionisnotwellunderstood.
Furthermore,whiletwosubjects(8and9)haddeletionsinvolvingotherexonsofNRXN1-aaswellasthisminorisoform,threesubjects'deletions(10–12)containonlytheexonofthisminorisoform.
ThisminorisoformisanEnsemblannotatedtranscript,namedENST00000406859(Fig.
1).
Itcontains13exonswith2,590bptranscriptionand856residuesoftranslationlength.
Thecodedprotein(ENSP00000385681)consistsofoneLNSandEGFdomain.
Itsfunctioniscurrentlyunknown.
Onesuchsubject(10)withadenovodeletioninthisregionhasbeendiagnosedwithPDD-NOS,suggestingpotentialclinicalrele-vanceforthisisoform.
Thisdeletioninintron5hasnottoourknowledgebeenpreviouslyreportedasbeingassociatedwithabnormaldevelopment.
Neurexin-1-bmutationswerelesscommon.
TwoofthesubjectsinourcohorthadlargedeletionsencompassingexonsforNRXN1-aand-b.
MissensevariantsinNRXN1-b(R8P,L13F,S14L,andT40S)havepreviouslybeenidentiedinindividualswithautism[Fengetal.
,2006;Kimetal.
,2008].
Relativesoftheseindividualswithautismwhosharedthesemissensemutationsdemonstratedsomedegreeoflearningorbehavioralissuesbutdidnotappeartomeetfullautismspectrumdisordercriteria[Fengetal.
,2006;Kimetal.
,2008].
Thisisconsistentwithourndingsofamixedphenotypeassociatedwithdeletionsinthisregionrangingfromautismspectrumdisorderstohypotoniawithcarrierrelativeswhoarenotasaffected.
InadditiontotheirNRXN1deletions,subjects8and11hadadditionalgenomicimbalancesasdescribedinTableI.
Thesegenomicimbalanceswereallinheritedfromunaffectedparents.
Thetwoduplicationson15q26.
3and17p11.
2insubject11overlapFIG.
2.
A:NRXN1-adeletionssegregatewithautismspectrumdisorder(ASD)andmildmentalretardation.
Pedigree1showsco-segregationofahemizygousCNVbetweenrs17041500andrs17512199whichdeletestherstthreecodingexons(DelEx1-3)ofNRXN1-a.
TheCNViscarriedbyallsubjectswithASDanddiminishedintelligencequotient(IQ),butnotbyatypicallydevelopingsibling.
Pedigree2showsco-segregationofahemizygousCNVwhichdeleteslikelyregulatory,genomicDNAupstream(Del50Reg)ofNRXN1-a.
PDD-NOS,pervasivedevelopmentdisorder,nototherwisespecied.
,wild-type,non-deletedDNA.
B:MappingofinferredCNdataSNP-by-SNPontheUCSCgenomebrowserdemonstratestheextentacrosstheNRXN1locus.
VerticalredlinesindicateeachSNPwithcopynumberof1or2.
Horizontalgreenlinesdemarcatetheextentofeachdeletion.
AlignmentofannotatedgenesintheRefSeqdatabaseareshownaswellasarepresentationofvertebrateconservationusingmultizandrelatedtoolsintheUCSC/PennStateBioinformaticscomparativegenomicalignmentpipeline.
Ofnote,Del50Regdeletesthelastfourexonsofanuncharacterized,splicedmRNAAK127244thatisexpressedinbrain.
ThegeneistranscribedintheoppositedirectionasNRXN1-ayetthetranscriptionstartsiteiswithin3.
5kbsuggestingthatthismRNAmaybetranscribedcoordinatelywithNRXN1-a.
[Colorgurecanbeviewedintheonlineissue,whichisavailableatwww.
interscience.
wiley.
com.
]944AMERICANJOURNALOFMEDICALGENETICSPARTBwithknownbenignCNVsandareunlikelycontributoryfactorstothepatient'scondition.
Theduplicationat5p13.
2insubject11anddeletionat3p24.
3insubject8arenotpreviouslyreportedCNVbutcontainnoknowngenesassociatedwithdevelopmentaldisorders,thusareconsideredasCNVofunknownsignicance.
Nevertheless,itisunclearwhethertheseCNVsmodiedtheobservedphenotype.
NRXN1andSynapseFunctionPriorstudieshavefunctionallylinkedothermoleculesthatareassociatedwithNRXN1toarangeofneuropsychiatricdisordersincludingautism.
Theseincludeneuroligins3and4(NLGN3,NLGN4)andSH3andmultipleankyrinrepeatdomains3(SHANK3)[Jamainetal.
,2002;Laumonnieretal.
,2004;Durandetal.
,2007;Moessneretal.
,2007;Lawson-Yuenetal.
,2008].
Inaddition,CNTNAP2(contactinassociatedprotein-like2)[Alarconetal.
,2008;Arkingetal.
,2008;Bakkalogluetal.
,2008]andcadherin10(CDH10)and9(CDH9)havebeenalsoassociatedwithautismspectrumdisorders[Wangetal.
,2009].
OurndingthatNRXN1isalsoassociatedwithautismanddevelopmentaldisordersaddsfurtherevidencetotheimportanceofthismolecularfamilytothedevelopmentofneurodevelopmentaldisorders.
ThefunctionofNRXN1infacilitatingsynaptictransmissionsuggeststhatmutationsinthisgenemaypredisposetoaneurologicdisconnectionsyndrome.
Long-rangedisconnectionsbetweenneuralnetworkshavebeenhypothesizedtobecausativeinsomepopulationswithautism[Barnea-Goralyetal.
,2004;Frith,2004;Justetal.
,2004;GeschwindandLevitt,2007].
TheeffectsofNRXN1onlanguagedevelopmentandhypotoniamaylikewiseberelatedtolong-rangeconnectivitywithinthebrain.
PhenotypicVariationPhenotypicvariationsmayreectthehighlypleiotropiceffectsobservedforspecicCNVssuchasthoseassociatedwithNRXN1.
Inaddition,anumberofoursubjectsinheritedNRXN1deletionsfromtheirparents.
Thedetailedphenotypeoftheseparentswerenotdescribedinthemedicalrecordsexceptinthefamilyhistory,buttheparentswereostensiblylessaffectedthantheirchildren.
ThissuggeststhatdeletionintheNRXN1genemaynotbefullypenetrant,orinteractswithothergenesresultinginthevariablephenotype.
Furtherresearcheffortstoinvestigatesuchvariablephenotypesassociatedwiththisunstablegenomicregionwillpro-videfurtherinsightintotheroleofNRXN1inthedevelopmentoflanguagedelays,autismspectrumdisorders,andphysicalfeatures.
LimitationsTheaccuracyandcompletenessoftheclinicalphenotypeidentiedinthisstudyisentirelydependentontheclinicalinformationthatwasdocumentedinthemedicalrecordsofthesesubjects,oftenbeforetheNRXN1deletionswereidentiedinthem.
Becauseoftheclinicalvariabilityexhibitedinourcohort,thesubjectswereseenbyavarietyofspecialists,whichaffectedthecompletenessofdata.
Inaddition,theparentswerenotformallyassessedtoascertaintheircognitive,physical,andbehavioralphenotypes.
Asnotedabove,reviewoffamilyhistorysuggeststhatsomeparentsmayhavesharedsimilarphenotypestotheirchildren.
Weareconduct-ingfurthertestingonboththesubjectsandtheirparentstobetterclarifydevelopmentaland/orsocialcognitionissuesinsubjectsandtheirparents.
ForthedeletionCNVsignicancetest,weusedthenormalcontroldatageneratedbydifferentgenomicprolingarrayplat-formsasreference.
Knowingthatthesensitivityandspecicitydifferfromonearrayplatformtoanother,thismaynotbeanoptimalcomparison.
However,theeffortwasmadetominimizethedetectionbiasbetweendifferentarrayplatforms.
Herewehaveonlychosenrecentstudiesusingarrayplatformofsimilarresolutionasours.
AllthesepublishedarticlesreportedthedetectionofsmallerCNV,suggestingthattechnicallyallthesearrayplatformswereabletodetectanyCNVidentiedinthisstudy.
Thusthiscomparison,althoughanapproximation,isontheconservativeside.
Finallyweacknowledgethatwhileourclinicallyascertainedsubjectswerenotdrawnfromacohortwithasinglediagnosissuchasautismorschizophrenia,theywereascertainedfromaheteroge-neouslyaffectedgroupinwhomgenetictestingwasconsideredclinicallyrelevant.
Asaresult,thereisascertainmentbiasandourndingsmaynotreectthetruedistributionofphysicalanddevelopmentalndingsintheNRXN1deletionphenotype.
Never-theless,wehavedemonstratedthatthereareanumberofotherphenotypicfeaturespresentinthisclinicalpopulationbeyondwhathaspreviouslybeenidentiedintheliterature.
CONCLUSIONWefoundawiderangeofphenotypicfeaturesinagroupofsubjectswithNRXN1deletionswhowereclinicallyreferredforgenetictesting.
Theseincludesubjectswithautismspectrumdisorders,mentalretardation,languagedelays,hypotonia,hemangiomas,andtheVACTERLassociation.
ACKNOWLEDGMENTSTheauthorsgratefullyacknowledgetheassistancebyourcolleaguesfromtheDNADiagnosticsLab:VaLip,XiaomingSheng,AnnReinhard,HongFang,SivTang,HongShao,HaitaoZhu,SamTang,andAndrewChengfortechnicalsupportofarrayCGH;ChristopherA.
WalshLab:DanielleGleasonandDanielRakiecfortechnicalsupportandRobertSeanHillforbioinformaticssupport.
WearefurthergratefulforthesupportfromtheNancyLurieMarksFamilyFoundation(C.
A.
W.
),theSimonsFoundation(C.
A.
W.
andJ.
F.
G.
),AutismSpeaks(J.
F.
G.
),andtheNIH(5K23MH080954-02toE.
M.
M.
and1R01MH083565toC.
A.
W).
E.
C.
E.
andC.
A.
W.
areInvestigatorsoftheHowardHughesMedicalInstitute.
Y.
S.
holdsaYoungInvestigatorAwardfromtheChildren'sTumorFoundationandCatalystAwardfromHarvardMedicalSchool,E.
M.
M.
holdsaCareerAwardforMedicalScientistsfromtheBurroughsWellcomeFund,B.
L.
W.
holdsaFudanScholarResearchAwardfromFudanUniversity.
REFERENCESAlarconM,AbrahamsBS,StoneJL,DuvallJA,PerederiyJV,BomarJM,SebatJ,WiglerM,MartinCL,LedbetterDH,etal.
2008.
Linkage,association,andgene-expressionanalysesidentifyCNTNAP2asanautism-susceptibilitygene.
AmJHumGenet82(1):150–159.
CHINGETAL.
945AracD,BoucardAA,OzkanE,StropP,NewellE,SudhofTC,BrungerAT.
2007.
Structuresofneuroligin-1andtheneuroligin-1/neurexin-1betacomplexrevealspecicprotein-proteinandprotein-Ca2interactions.
Neuron56(6):992–1003.
ArkingDE,CutlerDJ,BruneCW,TeslovichTM,WestK,IkedaM,ReaA,GuyM,LinS,CookEH,etal.
2008.
AcommongeneticvariantintheneurexinsuperfamilymemberCNTNAP2increasesfamilialriskofautism.
AmJHumGenet82(1):160–164.
BakkalogluB,O'RoakBJ,LouviA,GuptaAR,AbelsonJF,MorganTM,ChawarskaK,KlinA,Ercan-SencicekAG,StillmanAA,etal.
2008.
Molecularcytogeneticanalysisandresequencingofcontactinassociatedprotein-like2inautismspectrumdisorders.
AmJHumGenet82(1):165–173.
Barnea-GoralyN,KwonH,MenonV,EliezS,LotspeichL,ReissAL.
2004.
Whitematterstructureinautism:Preliminaryevidencefromdiffusiontensorimaging.
BiolPsychiatry55(3):323–326.
BierutLJ,MaddenPA,BreslauN,JohnsonEO,HatsukamiD,PomerleauOF,SwanGE,RutterJ,BertelsenS,FoxL,etal.
2007.
Novelgenesidentiedinahigh-densitygenomewideassociationstudyfornicotinedependence.
HumMolGenet16(1):24–35.
ChenX,LiuH,ShimAH,FociaPJ,HeX.
2008.
Structuralbasisforsynapticadhesionmediatedbyneuroligin-neurexininteractions.
NatStructMolBiol15(1):50–56.
ComolettiD,GrishaevA,WhittenAE,TsigelnyI,TaylorP,TrewhellaJ.
2007.
Synapticarrangementoftheneuroligin/beta-neurexincomplexrevealedbyX-rayandneutronscattering.
Structure15(6):693–705.
DudanovaI,SedejS,AhmadM,MasiusH,SargsyanV,ZhangW,RiedelD,AngensteinF,SchildD,RupnikM,etal.
2006.
Importantcontributionofalpha-neurexinstoCa2-triggeredexocytosisofsecretorygranules.
JNeurosci26(41):10599–10613.
DudanovaI,TabuchiK,RohlmannA,SudhofTC,MisslerM.
2007.
Dele-tionofalpha-neurexinsdoesnotcauseamajorimpairmentofaxonalpathndingorsynapseformation.
JCompNeurol502(2):261–274.
DurandCM,BetancurC,BoeckersTM,BockmannJ,ChasteP,FauchereauF,NygrenG,RastamM,GillbergIC,AnckarsaterH,etal.
2007.
Muta-tionsinthegeneencodingthesynapticscaffoldingproteinSHANK3areassociatedwithautismspectrumdisorders.
NatGenet39(1):25–27.
FengJ,SchroerR,YanJ,SongW,YangC,BockholtA,CookEH,SkinnerC,SchwartzCE,SommerSS.
2006.
Highfrequencyofneurexin1betasignalpeptidestructuralvariantsinpatientswithautism.
NeurosciLett409(1):10–13.
FrithC.
2004.
IsautismadisconnectiondisorderLancetNeurol3(10):577.
GeschwindDH,LevittP.
2007.
Autismspectrumdisorders:Developmentaldisconnectionsyndromes.
CurrOpinNeurobiol17(1):103–111.
GlessnerJT,WangK,CaiG,KorvatskaO,KimCE,WoodS,ZhangH,EstesA,BruneCW,BradeldJP,etal.
2009.
Autismgenome-widecopynumbervariationrevealsubiquitinandneuronalgenes.
Nature459(7246):569–573.
GrafER,ZhangX,JinSX,LinhoffMW,CraigAM.
2004.
NeurexinsinducedifferentiationofGABAandglutamatepostsynapticspecializationsvianeuroligins.
Cell119(7):1013–1026.
IchtchenkoK,HataY,NguyenT,UllrichB,MisslerM,MoomawC,SudhofTC.
1995.
Neuroligin1:Asplicesite-specicligandforbeta-neurexins.
Cell81(3):435–443.
IchtchenkoK,NguyenT,SudhofTC.
1996.
Structures,alternativesplicing,andneurexinbindingofmultipleneuroligins.
JBiolChem271(5):2676–2682.
InternationalSchizophreniaConsortium.
2008.
Rarechromosomaldele-tionsandduplicationsincreaseriskofschizophrenia.
Nature455(7210):237–241.
ItsaraA,CooperGM,BakerC,GirirajanS,LiJ,AbsherD,KraussRM,MyersRM,RidkerPM,ChasmanDI,etal.
2009.
Populationanalysisoflargecopynumbervariantsandhotspotsofhumangeneticdisease.
AmJHumGenet84(2):148–161.
JamainS,BetancurC,QuachH,PhilippeA,FellousM,GirosB,GillbergC,LeboyerM,BourgeronT,ParisAutismResearchInternationalSibpairS.
2002.
Linkageandassociationoftheglutamatereceptor6genewithautism.
MolPsychiatry7(3):302–310.
JustMA,CherkasskyVL,KellerTA,MinshewNJ.
2004.
Corticalactivationandsynchronizationduringsentencecomprehensioninhigh-function-ingautism:Evidenceofunderconnectivity.
Brain127(Pt8):1811–1821.
KentWJ,SugnetCW,FureyTS,RoskinKM,PringleTH,ZahlerAM,HausslerD.
2002.
ThehumangenomebrowseratUCSC.
GenomeRes12(6):996–1006.
KimHG,KishikawaS,HigginsAW,SeongIS,DonovanDJ,ShenY,LallyE,WeissLA,NajmJ,KutscheK,etal.
2008.
Disruptionofneurexin1associatedwithautismspectrumdisorder.
AmJHumGenet82(1):199–207.
KirovG,GumusD,ChenW,NortonN,GeorgievaL,SariM,O'DonovanMC,ErdoganF,OwenMJ,RopersHH,etal.
2008.
ComparativegenomehybridizationsuggestsaroleforNRXN1andAPBA2inschizophrenia.
HumMolGenet17(3):458–465.
LaumonnierF,Bonnet-BrilhaultF,GomotM,BlancR,DavidA,MoizardMP,RaynaudM,RonceN,LemonnierE,CalvasP,etal.
2004.
X-linkedmentalretardationandautismareassociatedwithamutationintheNLGN4gene,amemberoftheneuroliginfamily.
AmJHumGenet74(3):552–557.
Lawson-YuenA,SaldivarJS,SommerS,PickerJ.
2008.
FamilialdeletionwithinNLGN4associatedwithautismandTourettesyndrome.
EurJHumGenet16(5):614–618.
MarshallCR,NoorA,VincentJB,LionelAC,FeukL,SkaugJ,ShagoM,MoessnerR,PintoD,RenY,etal.
2008.
Structuralvariationofchro-mosomesinautismspectrumdisorder.
AmJHumGenet82(2):477–488.
MisslerM,SudhofTC.
1998.
Neurexins:Threegenesand1001products.
TrendsGenet14(1):20–26.
MisslerM,ZhangW,RohlmannA,KattenstrothG,HammerRE,Gott-mannK,SudhofTC.
2003.
Alpha-neurexinscoupleCa2channelstosynapticvesicleexocytosis.
Nature423(6943):939–948.
MoessnerR,MarshallCR,SutcliffeJS,SkaugJ,PintoD,VincentJ,ZwaigenbaumL,FernandezB,RobertsW,SzatmariP,etal.
2007.
ContributionofSHANK3mutationstoautismspectrumdisorder.
AmJHumGenet81(6):1289–1297.
MorrowEM,YooSY,FlavellSW,KimTK,LinY,HillRS,MukaddesNM,BalkhyS,GasconG,HashmiA,etal.
2008.
Identifyingautismlociandgenesbytracingrecentsharedancestry.
Science321(5886):218–223.
NagaseT,IshikawaK,MiyajimaN,TanakaA,KotaniH,NomuraN,OharaO.
1998.
Predictionofthecodingsequencesofunidentiedhumangenes.
IX.
Thecompletesequencesof100newcDNAclonesfrombrainwhichcancodeforlargeproteinsinvitro.
DNARes5(1):31–39.
NamCI,ChenL.
2005.
Postsynapticassemblyinducedbyneurexin-neuroligininteractionandneurotransmitter.
ProcNatlAcadSciUSA102(17):6137–6142.
NeedAC,GeD,WealeME,MaiaJ,FengS,HeinzenEL,ShiannaKV,YoonW,KasperaviciuteD,GennarelliM,etal.
2009.
Agenome-wideinvestigationofSNPsandCNVsinschizophrenia.
PLoSGenet5(2):e1000373.
NussbaumJ,XuQ,PayneTJ,MaJZ,HuangW,GelernterJ,LiMD.
2008.
Signicantassociationoftheneurexin-1gene(NRXN1)withnicotinedependenceinEuropean-andAfrican-Americansmokers.
HumMolGenet17(11):1569–1577.
946AMERICANJOURNALOFMEDICALGENETICSPARTBPuschelAW,BetzH.
1995.
Neurexinsaredifferentiallyexpressedintheembryonicnervoussystemofmice.
JNeurosci15(4):2849–2856.
RujescuD,IngasonA,CichonS,PietilainenOP,BarnesMR,ToulopoulouT,PicchioniM,VassosE,EttingerU,BramonE,etal.
2009.
Disruptionoftheneurexin1geneisassociatedwithschizophrenia.
HumMolGenet18(5):988–996.
SudhofTC.
2008.
Neuroliginsandneurexinslinksynapticfunctiontocognitivedisease.
Nature455(7215):903–911.
SugitaS,SaitoF,TangJ,SatzJ,CampbellK,SudhofTC.
2001.
Astoichiometriccomplexofneurexinsanddystroglycaninbrain.
JCellBiol154(2):435–445.
SzatmariP,PatersonAD,ZwaigenbaumL,RobertsW,BrianJ,LiuXQ,VincentJB,SkaugJL,ThompsonAP,SenmanL,etal.
2007.
Mappingautismrisklociusinggeneticlinkageandchromosomalrearrangements.
NatGenet39(3):319–328.
TabuchiK,SudhofTC.
2002.
Structureandevolutionofneurexingenes:Insightintothemechanismofalternativesplicing.
Genomics79(6):849–859.
UllrichB,UshkaryovYA,SudhofTC.
1995.
Cartographyofneurexins:Morethan1000isoformsgeneratedbyalternativesplicingandexpressedindistinctsubsetsofneurons.
Neuron14(3):497–507.
UshkaryovYA,PetrenkoAG,GeppertM,SudhofTC.
1992.
Neurexins:Synapticcellsurfaceproteinsrelatedtothealpha-latrotoxinreceptorandlaminin.
Science257(5066):50–56.
VrijenhoekT,Buizer-VoskampJE,vanderSteltI,StrengmanE,GeneticR,SabattiC,GeurtsvanKesselA,BrunnerHG,OphoffRA,etal.
2008.
OutcomeinPsychosisC.
RecurrentCNVsdisruptthreecandidategenesinschizophreniapatients.
AmJHumGenet83(4):504–510.
WalshT,McClellanJM,McCarthySE,AddingtonAM,PierceSB,CooperGM,NordAS,KusendaM,MalhotraD,BhandariA,etal.
2008.
Rarestructuralvariantsdisruptmultiplegenesinneurodevelopmentalpath-waysinschizophrenia.
Science320(5875):539–543.
WangK,ZhangH,MaD,BucanM,GlessnerJT,AbrahamsBS,SalyakinaD,ImielinskiM,BradeldJP,SleimanPM,etal.
2009.
Commongeneticvariantson5p14.
1associatewithautismspectrumdisorders.
Nature459(7246):528–533.
YanJ,NoltnerK,FengJ,LiW,SchroerR,SkinnerC,ZengW,SchwartzCE,SommerSS.
2008.
Neurexin1alphastructuralvariantsassociatedwithautism.
NeurosciLett438(3):368–370.
ZahirFR,BarossA,DelaneyAD,EydouxP,FernandesND,PughT,MarraMA,FriedmanJM.
2008.
Apatientwithvertebral,cognitiveandbehav-iouralabnormalitiesandadenovodeletionofNRXN1alpha.
JMedGenet45(4):239–243.
ZengZ,SharpeCR,SimonsJP,GoreckiDC.
2006.
Theexpressionandalternativesplicingofalpha-neurexinsduringXenopusdevelopment.
IntJDevBiol50(1):39–46.
ZhangW,RohlmannA,SargsyanV,AramuniG,HammerRE,SudhofTC,MisslerM.
2005.
Extracellulardomainsofalpha-neurexinsparticipateinregulatingsynaptictransmissionbyselectivelyaffectingN-andP/Q-typeCa2channels.
JNeurosci25(17):4330–4342.
CHINGETAL.
947
- 1.www.4411b.com相关文档
- bidirectionalwww.4411b.com
- 器件www.4411b.com
- presentwww.4411b.com
- CABLEwww.4411b.com
- Enterwww.4411b.com
- maintainwww.4411b.com
EdgeNat 新年开通优惠 - 韩国独立服务器原生IP地址CN2线路七折优惠
EdgeNat 商家在之前也有分享过几次活动，主要提供香港和韩国的VPS主机，分别在沙田和首尔LG机房，服务器均为自营硬件，电信CN2线路，移动联通BGP直连，其中VPS主机基于KVM架构，宿主机采用四路E5处理器、raid10+BBU固态硬盘！最高可以提供500Gbps DDoS防御。这次开年活动中有提供七折优惠的韩国独立服务器，原生IP地址CN2线路。第一、优惠券活动EdgeNat优惠码（限月...
百纵科技,美国独立服务器 E52670*1 32G 50M 200G防御 899元/月
百纵科技:美国高防服务器,洛杉矶C3机房 独家接入zenlayer清洗 带金盾硬防,CPU全系列E52670、E52680v3 DDR4内存 三星固态盘阵列！带宽接入了cn2/bgp线路，速度快，无需备案，非常适合国内外用户群体的外贸、搭建网站等用途。C3机房，双程CN2线路，默认200G高防，3+1（高防IP），不限流量，季付送带宽美国洛杉矶C3机房套餐处理器内存硬盘IP数带宽线路防御价格/月套...
virmach：3.23美元用6个月，10G硬盘/VirMach1核6个月Virmach
virmach这是第二波出这种一次性周期的VPS了，只需要缴费1一次即可，用完即抛，也不允许你在后面续费。本次促销的是美国西海岸的圣何塞和美国东海岸的水牛城，周期为6个月，过后VPS会被自动且是强制性取消。需要临时玩玩的，又不想多花钱的用户，可以考虑下！官方网站：https://www.virmach.comTemporary Length Service Specials圣何塞VPS-一次性6个...
www.4411b.com为你推荐
-
特朗普取消访问丹麦特朗普专机抵达日本安保警力情形如何？bbs.99nets.com怎么制作RO单机xyq.163.cbg.com梦幻CBG的网站是什么。seo优化工具想找一个效果好的SEO优化软件使用，在网上找了几款不知道哪款好，想请大家帮忙出主意，用浙江哪款软件效果好同一服务器网站一个服务器放多个网站怎么设置?mole.61.com摩尔庄园的米米号和密码我都忘了 只记得注册的邮箱 怎么办-_-m.2828dy.comwww.dy6868.com这个电影网怎么样?www.kanav001.com跪求下载[GJOS-024] 由愛可奈 [Kana Yume] 現役女子高生グラビア种子的网址谁有m.kan84.net那里有免费的电影看？partnersonline电脑内一切浏览器无法打开