Common Genes Implicated in Autism Study | WPN World People News

Most of the genetic risk for autism appears to come from common gene variants rather than spontaneous gene mutations, according to a new study.

Researchers compared about 3,000 people in Sweden with and without autism and found that about 52 percent of autism was linked to common gene variants and rare inherited variations. Spontaneous genetic mutations accounted for only 2.6 percent of autism risk.

The investigators also found that genetics seem to play a stronger role in autism risk than environmental factors, according to the study.

"From this study, we can see that genetics plays a major role in the development of autism compared to environmental risk factors, making autism more like height than we thought -- many small risk factors add up, each pushing a person further out on the spectrum," expert said.

Autism spectrum disorders describe a range of developmental disabilities that can cause social, communication and behavioral difficulties. About 1 in 68 U.S. children has an autism spectrum disorder, the U.S. Centers for Disease Control and Prevention estimates.

"Genetic variation likely accounts for roughly 60 percent of the liability for autism, with common variants comprising the bulk of its genetic architecture," expert said.

"Although each exerts just a tiny effect individually, these common variations in the genetic code add up to substantial impact, taken together," expert explained.

"Knowing the nature of the genetic risk will help focus the search for clues to the molecular roots of the disorder. Common variation may be more important than we thought," expert said.

Expert explained that "within a given family, the mutations could be a critical determinant that leads to the manifestation of [autism] in a particular family member."

Expert concluded: "The family may have common variation that puts it at risk, but if there is also a [new] mutation on top of that, it could push an individual over the edge. So for many families, the interplay between common and spontaneous genetic factors could be the underlying genetic architecture of the disorder."

Source: HealthDay News