Abstract
Autistic disorder (AD) is a developmental disorder affecting social interactions, communication, and behavior. AD is a disease of complex genetic architecture. It is postulated that several genes contribute to the underlying etiology of AD. Chromosome 15 is of particular interest due to numerous reports of AD in the presence of chromosomal abnormalities, located mainly in the 15q11-q13 region. There are also a number of plausible candidate genes in this area, including the gamma-aminobutyric acidA (GABA(A)) receptor gene complex. We have undertaken a study of this region of chromosome 15 in a data set of 63 multiplex families (with 2 or more AD affected individuals per family). We found evidence in support of linkage to the 15q11-q13 region, as well as evidence of increased recombination in this region. These findings provide further support for the involvement of chromosome 15q11-q13 in the genetic etiology of AD.