Autistic spectrum disorder associated with partial duplication of chromosome 15; three case reports.

Duplication of part or the entirety of chromosome 15 that involves the Prader-Willi/Angelman syndrome critical region (PWACR) is a genetic disorder which is associated with variable degrees of intellectual impairment, motor co-ordination problems and social and communication disorders. Published case reports indicate that phenotypic expression is dependent on parental origin of the duplication and implicate maternally derived duplications in the pathogenesis of autistic features. This article describes three individuals, two males and one female, aged between 5 and 8 years, all with partial duplication of chromosome 15. Autism (or autistic spectrum disorder) was present in all three instances with varying degrees of cognitive impairment. The aim of this paper is to describe the phenotypic characteristics of this genetic sequence and the possible associations between social and behavioural patterns on the one hand, and degree and nature of genetic impairment on the other.