New Study Gives Clues to Why Autism More Common in Boys

A recent U.S. study has identified a new gene variant may increase the risk of autism especially among boys.  Researchers at David Geffen School of Medicine at the University of California, Los Angeles, have analyzed the DNA of over 1,000 people whose families have at least two sons affected by autism.

Studies show that a variant of the gene CACNA1G, located on chromosome 17, is consistently associated with autism.  This variant of the gene, which helps move calcium between cells, has been found in about 40 percent of those studied.

Dr. Stanley Nelson, a school’s professor of human genetics, says that the finding is a strong one, as no one has scrutinized the role that CACNA1G plays in autism.

"We found that a common form of the gene occurs more frequently in the DNA of families that have two or more sons affected by autism, but no affected daughters," Nelson adds.  "Our study may explain why boys are more susceptible to the disorder than girls."

Boys are four times more at risk of autism compared to girls.

The study, however, does not determine how the variant of CACNA1G contributes to autism risk.  But Nelson said it cannot be considered a risk factor on its own.

The study appears online in the journal Molecular Psychiatry.