Study advances insight into autism's genetic hot spots

Findings support the multifactorial nature of this neurodevelopmental disorder and give hope for the discovery of biological targets for therapies; vaccine link still questioned.

By Stephanie Stapleton, AMNews staff. Sept. 17, 2001.

Mapping Disease
As the results of the Human Genome Project began to shake out into clinical applications, this 2001-02 series detailed progress in the prevention and treatment of a variety of diseases and conditions -- both on the near horizon and possibilities far into the future.

Washington -- Science is one step closer to unlocking the genetic basis of autism -- the puzzling neurodevelopmental disorder that effects, in some form, at least one in 500 people.

Researchers have identified the regions of four chromosomes that appear to be linked with the disorder, according to a study supported by the National Institutes of Health and published in this month's American Journal of Human Genetics.

"These findings confirm the role of genetics in autism and are a major step in narrowing the search for the specific genes involved," said Duane Alexander, MD, director of NIH's National Institute of Child Health and Human Development and co-chair of NIH's Autism Coordinating Committee.

The idea that there is an inherited component to autism is not new. Earlier studies have offered varying degrees of evidence. This study is important because it "is another link in this chain," said Marie Bristol-Power, PhD, the NICHD special assistant for autism. "This paper replicates findings on two of the genetic hot spots."

Specifically, the researchers screened the DNA of more than 150 pairs of siblings with autism -- all of whom were diagnosed using the same methods. The study, involving subjects and researchers from seven countries, was carried out by members of the International Molecular Genetic Study of Autism Consortium.

They found evidence that two regions on chromosomes 2 and 7 contain genes involved in the disorder.

"The chromosomes they are on make sense in terms of autism," said Dr. Bristol-Power. Chromosome 7 is known to be associated with many language disorders and has been shown to be linked with autism in some earlier studies, but not all. [...]