The study, published in the journal Science Translational Medicine, also showed that this increased brain connectivity in the frontal lobe was associated with fewer connections to other parts of the brain, leading researchers to believe that this latest risk gene may be responsible for "rewiring" of the brain.
The gene variant known as CNTNAP2 was also present in some of the non-autistic children in the study, and those children showed greater activity in the frontal lobe with weaker connections from there to other parts of the brain as well. But those kids did not have autism, meaning that this single gene variant is likely not responsible for the disease itself.
"We have known for some time that in most cases a single gene is not causative for autism," one of the study authors, Dr. Susan Bookheimer, professor of cognitive neurosciences at the University of California, told AOL Health. "These risk genes are fairly common." She says autism is caused by a variety of factors, including other gene variants, gene-to-gene interactions, as well as environmental factors."