In a collaboration involving 13 institutions around the world, researchers have broken new ground in understanding what causes autism. The results were recently published in Cell magazine.
“We finally have a clear-cut case of an autism-specific gene,” says Raphael Bernier, PhD, lead study author. Bernier says people with a mutation in the CHD8 gene have a very “strong likelihood” that they will have autism marked by gastrointestinal disorders, a larger head, and wide set eyes. In their study of 6,176 children with autism spectrum disorder, researchers found 15 had a CHD8 mutation, and all these cases had similar characteristics in appearance and issues with sleep disturbance and gastrointestinal problems.
Bernier says this is the first time researchers have linked a definitive cause of autism to a genetic mutation. Although less than half a percent of all children will have this kind of autism related to the CHD8 mutation, Bernier says the results could lead the way to a “genetics-first approach” that could uncover hundreds more genetic mutations and lead to genetic testing. Such testing could be offered to families as a way of guiding them on what to expect and how to care for their child. Currently, autism is diagnosed based on behavior, says Bernier.
Researchers say autism has currently been linked to different types of genetic events. The most commonly researched genetic events associated with autism are chromosomal rearrangements, called “copy number variations,” in which a chunk of chromosome is copied or deleted. While these copy number events are associated with autism, they do not have a definitive link, a “strong penetrance.” The CHD8 gene mutation is the first gene mutation to show a very strong penetrance linked to a certain subtype of autism. Read the study summary.Read more