Largest collection of autism DNA

Preliminary findings from the largest genome scan ever completed in the history of autism research are being published in Nature Genetics. University of Pittsburgh researchers with a consortium of scientists from across the world contributed to this landmark research endeavor through the Autism Genome Project.

The data represent the first phase of the effort, which was to assemble the largest collection of autism DNA and complete the whole genome linkage scan.

The collaboration is funded by Autism Speaks, a non-profit organization dedicated to increasing awareness of autism and raising money to fund autism research, and the National Institutes of Health.

This research was performed by more than 120 scientists from more than 50 institutions representing 19 countries who formed a first-of-its-kind autism genetics consortium, the Autism Genome Project (AGP). The AGP began in 2002 when researchers from around the world decided to come together and share samples, data and expertise to facilitate the identification of autism susceptibility genes. "This project represents a new beginning in autism research, and provides an invaluable resource to researchers worldwide," said Bernie Devlin, Ph.D., associate professor of psychiatry and human genetics at the University of Pittsburgh and a corresponding author of the study.

"We hope that access to the tools and information developed through this project will help researchers begin to unravel the causes of autism."

The consortium leveraged the unprecedented statistical power generated by its unique sample set by using "gene chip" technology to look for genetic commonality in autistic individuals culled from almost 1,200 families. The AGP also scanned these families' DNA for copy number variations (CNV), or sub-microscopic genomic insertions and deletions that scientists believe might be involved with this and other common diseases. The innovative combination of these two approaches implicates a previously unidentified region of chromosome 11 and neurexin 1, a member of a gene family believed to be important in contact and communication between neurons, among other regions and genes in the genome. The neurexin finding, in particular, highlights a special group of neurons, called glutamate neurons, and the genes affecting their development and function, suggesting they play a critical role in autism spectrum disorders.

"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," said 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 will provide profound new insight into the basis of autism, offering a route to breakthroughs in diagnosis and new treatments in support of families.

Autism is a complex brain disorder that inhibits a person's ability to communicate and develop social relationships, and often is accompanied by extreme behavioral challenges. Autism Spectrum Disorders are diagnosed in one in 166 children in the United States, affecting four times as many boys as girls. The diagnosis of autism has increased tenfold in the last decade. The Centers for Disease Control and Prevention have called autism a national public health crisis for which a cause and cure remain unknown.