Small Region of Chromosome 13 Contains Gene Linked to Autism

North Carolina researchers have identified a short region of chromosome 13--one of the 23 pairs of chromosomes that make up the human genetic blueprint--that contains a gene linked to autism. Although environmental factors play a role in autism, genetics is also thought to be important. In 90% of identical twins in which one has the disorder, the second does as well. Families with one autistic child have a 5% chance of having a second--much higher than the normal risk.

Dr. Joseph Piven and his colleagues studied 75 families with at least two autistic children. They report in the Dec. 15 American Journal of Medical Genetics that all the victims share a small region of DNA on chromosome 13, and they hope to identify a specific gene soon. The research also suggests the presence of a related gene on chromosome 7.