Large study provides new insights in autism’s genetic code

Thursday, February 22, 2007

In the largest study of its kind, a genetic analysis of 1,168 families with multiple cases of autism has identified genetic links to autism. A previously overlooked stretch of DNA on chromosome 11 implicates a gene called neurexin 1 and increases the evidence for the involvement of neurexins and genes related to glutamate transmission in the brain.

Genetic studies of autism have previously been undertaken; however the new study involves the collaboration of more than 120 scientists from more than 50 institutions representing 19 countries who pooled their data as part of the Autism Genome Project. The findings were published in the Feb. 18 issue of Nature Genetics.

Bob Wright, co-founder of Autism Speaks, a non-profit organization dedicated to increasing awareness of autism, said: “The identification of susceptibility genes will provide profound new insight into the basis of autism offering a route to breakthroughs in new treatments in support of families.” Autism Speaks funded this project in conjunction with the U.S. National Institutes of Health.

Joachim Hallmayer, MD, associate professor of psychiatry at Stanford and chair of the collaboration’s executive committee, explains what is next: “While promising, these results need to be followed up with more refined genetic maps to home in on other specific candidate genes. We also need to look more closely at chromosomal anomalies in large samples of children with autism.” In the paper, researchers caution that the genetic foundation of autism probably involves multiple genes and chromosomal abnormalities.

Autism affects about one in every 150 children, and the CDC has called it an “urgent health concern”. Autism is a developmental disorder which impairs social interaction, communication and features restricted and repetitive interests and activities. Twin studies and other research clearly suggest a genetic basis for the condition. Currently there is no cure for autism, but both behavioral or sensory interventions and drugs can influence the symptoms.