By Ilana Messika
Israeli researchers say that the discovery of a unique evolutionary signature in genes associated with Autism Spectrum Disorder (ASD) could lead to a better understanding of the genetic nature of the syndrome. That, in turn, could lead to a range of targeted therapies for the condition.
“[Our discovery will] aid in better understanding the biological mechanisms involved in autism development,” said Dr. Idan Menashe, the lead researcher and co-author of The Unique Evolutionary Signature of Genes Associated with Autism Spectrum Disorder, published in Behavior Genetics, a prominent medical industry journal. Speaking to Tazpit Press Service (TPS), Menashe said the discovery would allow scientists to focus on a specific biological target when developing future therapies for autism.
In a study conducted with Mr. Erez Tsur, and Prof. Michael Friger of Ben-Gurion University of the Negev in Be’er Sheva, the researchers found that 651 gene sequences taken from autistic individuals held common characteristics of autism-associated genes in contrast to other disease-related genomes. They said the finding provides an important opening towards understanding the genetic basis of the syndrome.
“The results of this research will help us to target more genes when we test for ASD and consequently expand the spectrum of identified cases,” Menashe said.
According to their research, the genes in question are longer than both healthy genes and genes that are afflicted with other types of abnormalities. In addition, the genes are less susceptible to the evolutionary process of negative selection: ASD are 20 percent less likely to mutate in expected ways over the course of multiple generations compared to other samples of genes.
“Some cases of autism are due to ‘de-novo’ mutations, which are mutations that were developed after fertilization, in the developing fetus,” Dr. Menashe explained.
“Second, some inherited mutations only cause autism when they are associated with other genetic or non-genetic risk factors. Therefore, if the mutations occur in the DNA without any other risk factor, they will not lead to autism and will possibly be passed on to future generations,” he stated.
Currently, ASD is diagnosed according to specific behavioral criteria that are defined by the Diagnostic and Statistical Manual of Psychiatric Disorders (DSM-V). The main characteristics shared by all children with autism are deficits in social communication, and restricted repetitive movements or behaviors.
The ‘Genetic Chip’ is a genetic examination to test few cases of autism already exist. However, although genetics plays a significant role in the disease’s development, there are strong indications for some cases of autism, that other non-genetic factors also contribute to the disorder.