Yale School of Medicine autism experts Fred R. Volkmar, M.D., and Ami Klin are part of a global research consortium from 19 countries that identified an individual gene and a region of a chromosome that may lead to autism in children.
The findings are published online in Nature Genetics and also will be published in the journal's March print edition. They are based on the largest autism genome scan done to date. The Autism Genome Project (AGP), including over 120 scientists from over 50 institutions who formed performed the research. The AGP began in 2002 when researchers from around the world decided to collaborate and share their samples, data and expertise to aid in identifying autism susceptibility genes.
Funded by Autism Speaks, a national non-profit organization dedicated to increasing awareness of autism and raising money to research the disorder, and the National Institutes of Health, these are the preliminary findings from the AGP's first phase.
The consortium used "gene chip" technology to look for genetic similarities in autistic individuals identified within almost 1,200 families. They also scanned the DNA to search for copy number variations, which are submicroscopic insertions and deletions of genetic material that scientists believe may be linked to autism and other disorders.
The researchers found a specific gene called neurexin 1. It is one of a family of genes that plays a role with the neurotransmitter glutamate, which has been previously linked to autism. They also identified a section of chromosome 11 that may contain a gene involved in autism susceptibility. That specific gene has not yet been pinpointed.
"We have known for years that autism is a strongly genetic disorder—this study helps us to significantly advance research on genetic mechanisms," said Volkmar, study co-author, Yale Child Study Center Director and the Irving B. Harris Professor of Child Psychiatry, Pediatrics and Psychology.
"The concerted effort of multiple agencies bringing together numerous research institutions has led to a new wave of genetic discoveries in autism that markedly change the landscape of knowledge about this highly prevalent disorder," said Klin, who together with Volkmar, coordinates the Autism Program at Yale.
"The discovery of genes associated with autism and their interactions needs now to set in motion an even stronger effort to develop new pharmacological treatments to change the natural course of this highly heterogeneous family of disorders of socialization," he said. "These are exciting times in this field."
Researchers speculate that there may be five or six primary genes and as many as 30 other genes involved in autism, although they recognize that this number could be higher still. They concede that it is still very early to model the ways in which these genes might bring about autism, but the rate of new discoveries is extremely promising.
Autism is a complex brain disorder that inhibits a person's ability to communicate and develop social relationships, and is often accompanied by extreme behavioral challenges. Autism Spectrum Disorders are diagnosed in one in 150 children in the United States, affecting four times as many boys as girls. The rates of identification of individuals with autism have increased tenfold in the last decade, reflecting a number of factors that include increased awareness of the condition, broadening of its definition, and better educational services.
Source: YALE University