The Genetics Of Autism
April 27, 2014

Copy Number Variant Testing Could Help Detect Autism

redOrbit Staff & Wire Reports - Your Universe Online

Rare copy number variations (CNVs) are more common in families that are affected by autism, suggesting that this type of genetic testing could prove to be an important tool in the individualized diagnosis and treatment of the condition, researchers from the Autism Genome Project claim in a new study.

In a report published in the April 24 edition of the American Journal of Human Genetics, the authors discuss the CNV testing of 2,446 families affected by autism and 4,768 individuals not impacted by neurological or psychiatric disorders. They found that these genetic changes involving the duplication or deletion of entire DNA segments were significantly more common in the first group.

In a statement, Autism Speaks - which funds the Autism Genome Project (AGP) – said that the newly published paper “delivers on the 10-year project's objective to provide practical methods for earlier diagnosis and personalized treatment of autism.” AGP’s research has involved over 50 research centers in 11 different countries.

“With the publication of this study, we should step back to recognize and celebrate the pioneering achievements of the AGP and what they have accomplished in helping to launch the field of genomic risk discovery in autism,” said Autism Speaks Chief Science Officer Rob Ring.

“The AGP has generated information that holds the potential to guide medical care for certain individuals with autism today. They have demonstrated that science can work for families, and Autism Speaks is proud to have been a supporter of the work all along the way,” he added.

Furthermore, the CNV testing was able to discover dozens of cases where genetic changes associated with autism could also be linked to other potentially serious health risks. For example, nine of the families affected by autism were found to have genetic changes indicative of an increased risk for epilepsy and seizures, and several others were found to have an elevated risk of muscular dystrophy or syndromes associated with heart conditions.

CNVs do not typically appear on standardized genetic tests that search only for the so-called spelling errors in the DNA letters that make up a gene, the study authors said. Those tests are normally able to identify a clear genetic link to autism in just approximately 15-20 percent of all cases. Furthermore, the study added dozens of additional genes to the list of those known to contribute to the development of autism.

“This report and its extensive supplements should become a new guidebook for medical geneticists working with families affected by autism,” senior author Dr. Stephen Scherer, of the Toronto's Hospital for Sick Children and the University of Toronto, explained. "These gene discoveries will help guide further research on autism subtypes and their treatment.”

Based on their findings, Dr. Scherer and his colleagues are urging medical geneticists to add CNV testing to standard gene tests for autism, and are also calling on these experts to consult medical recommendations for the several conditions associated with autism that can also be revealed through the CNV testing process.