Posted on by Dr. Francis Collins
We know that a combination of genetic and environmental factors influence a child’s risk of autism spectrum disorder (ASD), which is a diverse group of developmental brain conditions that disrupt language, communication, and social interaction. Still, there remain a great many unknowns, including the crucial issues of what proportion of ASD risk is due to genes and what sorts of genes are involved. Answering such questions may hold the key to expanding our understanding of the disorder—and thereby to devising better ways to help the millions of Americans whose lives are touched by ASD .
Last year, I shared how NIH-funded researchers had identified rare, spontaneous genetic mutations that appear to play a role in causing ASD. Now, there’s additional news to report. In the largest study of its kind to date, an international team supported by NIH recently discovered that common, inherited genetic variants, acting in tandem with each other or with rarer variants, can also set the stage for ASD—accounting for nearly half of the risk for what’s called “strictly defined autism,” the full-blown manifestation of the disorder. And, when the effects of both rare and common genetic variants are tallied up, we can now trace about 50 to 60 percent of the risk of strictly defined autism to genetic factors.