LA Times: Autism linked to hundreds of gene mutations

Thursday, June 9, 2011 at 03:43 PM

By Shari Roan
Los Angeles Times

LOS ANGELES — Autism is not caused by one or two gene defects but probably by hundreds of mutations, many of which arise spontaneously, according to research that examined the genetic underpinnings of the disorder in more than 1,000 families.

The findings were reported in three studies published Wednesday in the journal Neuron.

They cast autism disorders as genetically complex, involving many potential changes that may produce, essentially, different forms of autism.

The affected genes appear to be part of a large network involved in controlling the development of synapses, the critical junctions between nerve cells that allow them to communicate, according to one of the studies.

Although the work will have no immediate value to patients or their families, the insights provide a wealth of targets to pursue in developing treatments for the disorder, scientists said. Understanding the genetic causes of autism spectrum disorders may promote more accurate diagnoses.

“For the first time we’re getting a sense of how many areas of the genome are likely to contribute to autism,” said Dr. Matthew State, associate professor of psychiatry and of genetics at Yale University and the lead investigator of one of the studies.

Autism spectrum disorders are a group of conditions, ranging from severe to mild, characterized by problems with social interactions. Those with autism may exhibit repetitive behaviors and narrow, obsessive interests; some may have low IQs or problems with language development. About one in 110 U.S. children have an autism spectrum disorder, according to the Centers for Disease Control and Prevention.

An estimated 25 percent of autism spectrum disorder cases are linked to inherited gene mutations passed from parent to child. Some of these high-risk genes have been identified. But researchers have been puzzled by the cause of the disorder in families with no history of autism.

One key question is what is causing the spontaneous mutations, said Irva Hertz-Picciotto, an autism researcher at the University of California, Davis, who was not involved in the studies.

Note: We know that answer – it’s the aborted fetal DNA! See all articles on Autism Research.