Preliminary Results Identify Genetic Mutations Associated with Autism

An international consortium of researchers, including Dr. Eric Fombonne, Director of Pediatric Psychiatry at the Montreal Children's Hospital of the MUHC, and participating families joined together to announce the publication of the preliminary results from the largest genome scan ever in autism research. The groundbreaking study is published in the new issue of Nature Genetics, one of the world's most prestigious research journals.

"The Autism Genome Project (AGP), which began in 2002, represents a unique opportunity for scientists from more than 50 institutions, representing 19 countries, to come together to share samples, data, and expertise to facilitate the identification of autism susceptibility genes," says Dr. Fombonne, an autism expert at the MUHC, co-author of the research and member of the steering committee of the AGP.

The 120 scientists involved in the AGP leveraged the unprecedented statistical power generated by this unique sample set by using "gene chip" technology to look for genetic commonality in autistic individuals from almost 1,200 families. The researchers also scanned DNA from these families for genetic mutations known as copy number variations (CNV), or sub-microscopic genomic insertions and deletions, that scientists believe might be involved with this and other common diseases.

"The phase one results published today reveal new genetic mutations associated with autism that were previously unknown," says Dr. Fombonne, a McGill University professor of psychiatry. "Specifically, the findings implicate a previously unidentified region of chromosome 11 that has been associated with brain development."

The study also highlights a special group of nerve cells, called glutamate neurons, and the genes affecting their development and function, suggesting they play a critical role in autism spectrum disorders.

"This research has brought us closer to the discovery of autism susceptibility genes, which will be welcome news for families dealing with this disorder," says Dr. Fombonne. "These exciting findings are also exemplary of how an international scientific collaboration fostered by family associations can be successful in elucidating the genetics of complex childhood diseases."

"By combining cutting edge CNV analysis with the more traditional linkage and association [analyses], the scientists now have a promising new experimental framework to look for autism susceptibility genes," adds Andy Shih, Autism Speaks chief science officer. "These exciting findings from the AGP linkage scan confirm the value and contribution of multidisciplinary collaboration to advancing autism research."

The AGP Consortium believes the identification of susceptibility genes in phase two of the project will provide profound new insights into the basis of autism, offering a route to breakthroughs in diagnosis and treatments in support of families.

Funding for this study was provided by in-part by Autism Speaks and the U.S. National Institutes of Health.