Parents and collateral relatives of children with pervasive developmental disorders: a family history study.

The objective of this study was to see whether, using the family history method, the risk for pervasive developmental disorder (PDD), cognitive impairments, and other psychiatric symptoms is greater in the parents and collateral relatives of probands with PDD compared to a control group. A semistructured family history interview was carried out with the parents of 52 probands with PDD and 33 parents of controls. Rates of cognitive impairments and psychiatric problems were not found more frequently in parents or relatives of PDD probands compared to relatives of controls, but four cases of PDD were reported among the extended families of the PDD probands. The relatives with PDD were related to the probands through the maternal line, possibly suggesting some form of maternal influence on inheritance or reduced penetrance in females with the PDD genotype.