Autism spectrum disorder is a complex neurodevelopmental condition that is likely caused by both genetic and environmental factors. As the name suggests, it also represents a range of symptoms and behaviors, all of which makes teasing apart the genes involved quite challenging.
In a study published in Cell, researchers led by Joseph Buxbaum, director of the Seaver Autism Center for Research and Treatment at Mount Sinai, took advantage of better genetic sequencing technologies and one of the largest databases of DNA samples from people with autism to identify 102 genes associated with autism, including 30 that had never before been connected with the condition. The study also distinguished the genes more closely associated with autism from those that might also contribute to other neurodevelopmental disorders including intellectual and motor disabilities, TIME reports.
“This is one of the most important, comprehensive studies on the genetics of autism to date,” says Dr. Geraldine Dawson, director of the Center for Autism and Brain Development at Duke University, who was not involved in the study. “The findings start to put into place a lot of pieces of the autism puzzle.”
The team analyzed more than 35,000 samples, including nearly 12,000 from people with autism that were collected by the Autism Sequencing Consortium, an international consortium of scientists co-founded by Buxbaum that has shared samples and data since 2010. By comparing genetic sequences from people with autism to their siblings, and to people not affected by the condition, the researchers were able to isolate both inherited gene mutations, as well as spontaneous, or de novo, genetic alterations that can arise during development after egg and sperm are fertilized, that could contribute to the condition.
One group of mutations, which stop the gene from making whatever protein or other compound it is supposed to, are the easiest to find, says Buxbaum, because their effect tends to be more obvious.