Scientists have discovered several gene mutations that increase the chances of developing autism. This is the first time researchers have pinpointed a specific genetic component with the spectrum of disorders, which also includes Asperger's.
Scientists found that the risk is higher in older parents, in particular new fathers over 35.
The mutations are rare and account for a small number of actual cases, which have reached the alarming rate of one in every 88 children, according to a Centers for Disease Control and Prevention report released last week.
The discovery of the mutations are significant because it gives scientists a road map to study Autism's biology. The New York Times reports that it could uncover enough rare mutations to account for up to 20 percent of Autism spectrum cases.
Some researchers, however, were more cautious about the significance of the research:
"This is a great beginning, and I'm impressed with the work, but we don't know the cause of these rare mutations, or even their levels in the general population," said Dr. Aravinda Chakravarti of the Institute of Genetic Medicine at the Johns Hopkins University Medical School, who was not involved in the studies. "I'm not saying it's not worth it to follow up these findings, but I am saying it's going to be a hard slog."
Three teams took a look at DNA taken from blood samples of families in which parents have no signs of autism, but have cases where their childred developed the disorder. They focused on rare genetic glitches called de novo mutations, which aren't inherited. It happened around the time of conception, and are common and usually harmless. Though, new studies indicate that kids with autism have a slightly higher rate.
One team studied 200 people with autism along with parents and siblings that did not have it. Two unrelated children with autism had de novo mutations in the same gene. The chances of coincidence are incredibly low. The other two teams came up with similar findings.
One group found that de novo mutations were four times more likely to come from DNA from dads rather than moms. As dads get older, it jives with research that associates older fathers with the increase in autism cases.
Its important to keep in mind that most of these diseases likely have both environmental and genetic components to it but at least this piece of research gives scientists a ground to work on for future work. [The New York Times, Nature]