Health News: Mutations in Autism Susceptibility Gene Increase Risk in Boys

Researchers at Emory University School of Medicine identified five rare mutations in a single gene that appear to increase the chances that a boy will develop an autism spectrum disorder (ASD).

Mutations in the AFF2 gene, and other genes like it on the X chromosome, may explain why autism spectrum disorders affect four times as many boys as girls. The results were published July 5 in the journal Human Molecular Genetics.

“Our data suggest that AFF2 could be one of the major X-linked risk factors for ASDs,” says senior author Michael Zwick, assistant professor of human genetics at Emory University School of Medicine.

“We do not think that the variants we have identified are monogenic causes of autism,” he says. “Our data does support the idea that this is an autism susceptibility gene.”

Tests showed that in four cases, the affected boys had inherited the risk-conferring mutations from their mothers. One boy had a “de novo” (not coming from the parents) mutation. Compared with X-linked genes in unaffected people, mutations in AFF2 were five times more abundant in the boys with ASDs.