A genetic research on more than 100 families prone to autism by Harvard researchers shed new light on the devastating disease affecting as many as 1 in every 150 children in the United States (according to the U.S. Centers for Disease Control and Prevention’s estimates) and might eventually lead to ways to treat it.

Study leaders Dr. Christopher A. Walsh and Dr. Eric Morrow of Harvard Medical School in Boston and colleagues studied 104 Muslim families from Pakistan, Turkey, Jordan, Saudi Arabia, Qatar and Kuwait. They especially turned to these families from the Middle East, because the Middle East is a part of the world with large families and a tendency for cousins to marry, characteristics that increase the chances that offspring will inherit rare mutations. In 88 of the families, first-cousin marriages were common. All had family members with autism.

“Marriages between first cousins increase the prevalence of neurological birth defect by about 100 percent” the researchers wrote in the July 11 issue of the journal Science.

The researchers found that autism in not only caused by the deletion of some genes but also by turning off other genes. These particular genes cause disruptions in the brain’s ability to form new connections in response to experience.

“The genes implicated in our study are ones that interact with the environment and are involved in how the brain converts what it sees from the environment. If we can activate those genes by other mechanism, we might be able to help the kids,” Dr. Walsh, a neurologist and chief of genetics at Children’s Hospital in Boston, said.

What the researchers found was the existence of six genes with mutations or missing pieces. Also, two of the six genes are known to be involved in the growth of axons, the tendrils that nerve cells send out to contact other cells.

More exactly, the findings suggest that many forms of autism result from specific defects that affect a child’s ability to learn and remember. Previous studies have shown that enriched learning environments with extra training can help reactivation of genes in some children with autism.

Dr. Gary Goldstein, a clinician at the Kennedy Kreiger Institute in Baltimore welcomed the findings calling them encouraging. He uses behavior therapy in autism patients and believes that the genes that are turned off for one reason or another could possibly be turned on with early interventions. “I was excited by this paper; it shows why this could possibly work. It’s because the genes that are underlying autism are capable of being turned back on,” he told ABC News.

Once these genes discovered, the researchers now need to find medications that can reactivate them faster and with better results than using toys, wheels and other devices and therapies to stimulate the brain.

Autism is a spectrum of different disorders ranging in severity and in symptoms from the mild Asperger’s syndrome to more severe autism, characterized by poor social interactions, impaired communication, and repetitious behaviors. Studies have shown that males are four times more likely to have autism than females.