Genetic clues to the biological basis of autism.

Autism, the prototypical pervasive developmental disorder, is characterized by impaired communication and social interaction, and by repetitive interests and behaviours. The core disorder probably affects around 5:10 000 individuals, of whom some three-quarters are male. Onset is in the first three years of life, and the disorder is associated with lifelong disabilities. Because of the clear evidence that idiopathic autism has a strong genetic basis, many groups are undertaking whole genome screens to identify susceptibility loci. We review the first results, and briefly consider the implications of molecular genetic findings for future research, diagnosis and management.