The variant helps move calcium between cells. "This is a strong finding," said Stanley Nelson, a human genetics professor at the David Geffen School of Medicine at the University of California Los Angeles, in a university news release. "No one has scrutinized the role that CACNA1G plays in autism."
Nelson said, "Our study may explain why boys are more susceptible to the disorder than girls."
Autism affects boys four times more often than girls.
The scientists have not determined how the variant increases autism risk. Researchers don't consider the gene to be a risk factor for autism on its own.
"This variant is a single piece of the puzzle," Nelson said. "We need a larger sample size to identify all of the genes involved in autism and to solve the whole puzzle of this disease."
The study appears online in the journal Molecular Psychiatry.