(Great Neck, N.Y. - July 09, 2009) — NARSAD 2006 Distinguished Investigator Maja Bucan, Ph.D., was co-author of a study that identified 27 different genetic regions where rare copy number variations -- missing or extra copies of DNA segments -- were found in the genes of children with autism spectrum disorders (ASDs), but not in healthy controls.
The research was conducted by a team from the University of Pennsylvania School of Medicine, the Children's Hospital of Philadelphia and several other collaborating institutions and reported on June 26 in the journal PloS Genetics.
“We are finding that both inherited and new, or de novo, genetic mutations are scattered throughout the genome, and it is becoming clear that different combinations of these variations contribute to autism susceptibility,” said Dr. Bucan, a genetics professor at the University of Pennsylvania School of Medicine and chair of the steering committee for the Autism Genetic Resource Exchange, (AGRE), a program of the organization Autism Speaks, in which families of children with autism spectrum disorders participate in genetic studies.
The researchers compared genetic samples of 3,832 individuals from 912 families with multiple autistic children from the AGRE cohort against genetic samples of 1,070 disease-free children. The study’s leader, Hakon Hakonarson, M.D., Ph.D., of Children’s Hospital of Philadelphia and the University of Pennsylvania School of Medicine, noted that many of the autism susceptibility genes identified are involved in the development of brain circuitry in early childhood. The team also discovered many mutations found only in one or a few individuals or families, an indication of the genetic complexity -- the many different gene changes -- that may contribute to an autism spectrum disorder.
The current study expands on earlier studies by the University of Pennsylvania team. One study was the first to report common gene variants in ASDs. Another identified copy number variants that raise the risk of having an ASD. Both studies found gene changes on two biological pathways with crucial roles in early central nervous system development. According to Drs.