Risk of autistic disorder in affected offspring of mothers with a glutathione S-transferase P1 haplotype.

Objective: To test whether polymorphisms of the glutathione S-transferase P1 gene (GSTP1) act in the mother during pregnancy to contribute to the phenotype of autistic disorder (AD) in her fetus.

Design: Transmission disequilibrium testing (TDT) in case mothers and maternal grandparents.

Setting: Autistic disorder may result from multiple genes and environmental factors acting during pregnancy and afterward.