BGU researchers have taken a step closer to understanding the genetic basis of autism.
Dr. Idan Menashe and his colleagues, Mr. Erez Tsur, and Prof. Michael Friger, studied the sequences of over 650 genes that are associated with autism and discovered characteristics that distinguish them from other genes in the genome. Their research was just published in Behavior Genetics.
Among the distinct characteristics of autism genes is their exceptional genomic length, which is even longer than other brain-expressed genes of closely related diseases such as Alzheimer’s disease and schizophrenia. Additionally, the authors found a unique genomic signature in these genes that was shaped by negative selection, an evolutionary process that removes disruptive mutations from genes over generations.
Menashe and his colleagues also searched for evidence of positive selection in these genes. Such a mechanism could explain the presence of autism in the human population. However, no indications of positive selection acting on autism genes were found. Thus, autism susceptibility mutations are maintained in the human genome probably because they cause the disorder only in combination with other genetic and/or non-genetic factors.
Finally, the authors used the unique genomic characteristics of autism genes to identify additional candidate genes for the disorder. They showed that this evolutionary signature is highly efficient in capturing well-established autism genes. These findings broaden our understanding about the genetic mechanisms that are involved in autism, and provide new tools for the discovery of new candidate genes.
Menashe and Tsur are members of the Department of Public Health, Faculty of Health Sciences, and the Zlotowski Center for Neuroscience. Friger is a member of the Department of Public Health.
