Genes Underlying Autism
The Genes Underlying Autism Are Coming Into Focus
As researchers sequence, the DNA of thousands of kids with autism, dozens of genetic subgroups are emerging.
In late 2013, psychologist Raphael Bernier welcomed a 12-year-old girl and her parents into his office at the University of Washington (UW) in Seattle. The girl had been diagnosed with autism spectrum disorder, and Bernier had invited the family in to discuss the results of a genetic analysis his collaborator, geneticist Evan Eichler, had performed in search of the cause.
As they chatted, Bernier noticed the girl’s wide-set eyes, which had a slight downward slant. Her head was unusually large, featuring a prominent forehead. The mother described how her daughter had gastrointestinal issues and sometimes wouldn’t sleep for two to three days at a time. The girl’s presentation was interesting, Bernier recalls, but he didn’t think too much of it—until a week later when he met an eight-year-old boy with similarly wide-set eyes and a large head.
Bernier did a double take. The “kiddos,” as he calls children who come to see him, could have been siblings. According to the boy’s parents, he also suffered from gastrointestinal and sleep problems. The similarities between the unrelated children were remarkable, especially for a disorder so notoriously complex that it has been said, “If you’ve met one child with autism, you’ve met one child with autism.” But Bernier knew that the patients shared another similarity that might explain the apparent coincidence: both harbored a mutation in a gene known as chromodomain helicase DNA-binding protein 8 (CHD8).
CHD8 produces a protein that regulates chromatin—the conglomeration of tightly packed DNA and proteins in the nucleus—during fetal development. A year earlier, Bernier and Eichler had screened the genomes of 2,000 children for mutations in genes suspected to be involved in autism.
Written by Megan Scudellari. Read more at Mobile.The-Scientist.com