AUTISM - THE PHENOTYPE IN RELATIVES

There is broad agreement that genetic influences are central in the de velopment of idiopathic autism. Whether relatives manifest genetically related milder phenotypes, and if so how these relate to autism prope r, has proved a more contentious issue. A review of the relevant studi es indicates that relatives are sometimes affected by difficulties tha t appear conceptually related to autistic behaviors. These range in se verity from pervasive developmental disorders to abnormalities in only one area of functioning, and possibly extend to related personality t raits. Issues involved in clarifying the components of milder phenotyp es and their relationship to autism are outlined.