High phenotypic correlations among siblings with autism and pervasive developmental disorders

✍ Scribed by Szatmari, Peter; Jones, Marshall B.; Holden, Jeannette; Bryson, Susan; Mahoney, William; Tuff, Larry; MacLean, Joanna; White, Bradley; Bartolucci, Giampiero; Schutz, Chris; Robinson, Paula; Hoult, Lorraine

• Book ID: 102645691
• Publisher: John Wiley and Sons
• Year: 1996
• Tongue: English
• Weight: 903 KB
• Volume: 67
• Category: Article
• ISSN: 0148-7299
• DOI: 10.1002/(sici)1096-8628(19960726)67:4<354::aid-ajmg7>3.0.co;2-m

✦ Synopsis

The objective of this study was to examine familial factors influencing clinical variation in sibships that contained at least 2 children affected with autism or another form of pervasive developmental disorder (PDD). The sample included a total of 60 families, 23 with multiple cases of PDD and 37 with a single affected child. Measurements of I&, adaptive behaviors in socialization and communication, and autistic symptoms were taken on all affected children. A high intraclass correlation, especially on I& and an index of social behaviors, was observed between affected children from the same family. In contrast, low correlations were observed on measurements of I& and adaptive behavior between affected and unaffected children from the same family. These data indicate that variation in severity of PDD is influenced by familial, and probably genetic, mechanisms. The results are discussed in relation to current theories on the genetics of autism and the heritable mechanisms underlying variations in clinical severity.