?url_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Adc&rft.title=Prenatal+development+of+monozygotic+twins+and+concordance+for+schizophrenia&rft.creator=Davis%2C+JO&rft.creator=Phelps%2C+JA&rft.creator=Bracha%2C+HS&rft.subject=Neuropsychiatry&rft.subject=Neurology&rft.description=While+twin+concordances+for+schizophrenia+have+been+used+to+estimate+heritability+and+to+develop+genetic+models%2C+concordances+in+subtypes+of+monozygotic+(MZ)+twins+can+also+be+used+to+investigate+the+influence+of+prenatal+development+in+the+etiology+of+mental+illness.+We+used+within-pair+variability+and+mirroring+of+fingerprints+to+estimate+retrospectively+the+placentation+status+of+concordant+and+discordant+MZ+twins.+The+results+indicate+that+concordant+MZ+pairs+were+more+likely+to+have+been+monochorionic+(MC)+and+to+have+shared+a+single+placenta%2C+whereas+discordant+MZ+pairs+appear+more+likely+to+have+been+dichorionic+(DC)+with+separate+placentas.+Pairwise+concordances+for+MZ+twins+without+MC+markers+averaged+10.7+percent.+In+contrast%2C+concordances+for+MZ+twins+with+one+or+more+MC+markers+averaged+60+percent.+This+suggests+that+simple+MZ+concordance+rates+may+overestimate+schizophrenia+heritability+and+that+prenatal+development+may+also+be+important+in+the+etiology+of+schizophrenia.+Because+MC+(but+not+DC)+twins+usually+share+fetal+blood+circulation+and+hence+are+likely+to+share+infections%2C+these+results+are+consistent+with+the+hypothesis+that+fetal+infections+may+be+a+significant+etiological+factor+in+schizophrenia.%0A&rft.date=1995&rft.type=Journal+(Paginated)&rft.type=PeerReviewed&rft.format=application%2Fpdf&rft.identifier=http%3A%2F%2Fcogprints.org%2F5314%2F1%2FBracha_et_al.%252C_Prenatal_Development_of_Monozygotic_Twins.PDF&rft.identifier=++Davis%2C+JO+and+Phelps%2C+JA+and+Bracha%2C+HS++(1995)+Prenatal+development+of+monozygotic+twins+and+concordance+for+schizophrenia.++%5BJournal+(Paginated)%5D+++++&rft.relation=http%3A%2F%2Fcogprints.org%2F5314%2F