The researchers found that one of the GABA receptor genes, GABRA4, is involved in the origin of autism. Moreover, they report, GABRA4 appears to increase autism risk through its interaction with a second GABA gene, GABRB1.
"This is a key finding for our understanding of the complexity of interactions that underlie autism," Pericak-Vance said. "We can now apply the analytical approach to other genes that may play a role in the disease." Such findings may ultimately yield a method to screen for individuals at high risk for the disease, she added.
"The new findings offer important new information for families affected by autism about the complexity of the disease," said clinical psychologist Michael Cuccaro, Ph.D., a study co-author also of the Duke Center for Human Genetics.
Furthermore, he added, existing medications already target the GABA system, including diazepam (Valium®) and some anti-epileptic drugs. "As we begin to understand the GABA system as it relates to the neurological underpinnings of autism, we may advance toward new therapies."
Collaborators on the study include D.Q. Ma, P.L. Whithead, M.M. Menold, E.R. Martin, A.E. Ashley-Koch, G.R. DeLong and J.R. Gilbert, all of Duke; H. Mei of North Carolina State University; M.D. Ritchie of Vanderbilt University; and H.H. Wright, Ruth Abramson of University of South Carolina.