Autism’s Unexpected Link to Cancer Gene
But rapamycin, which targets the tuberous sclerosis gene and blocks a protein involved in cell division, changed the animals. They no longer compulsively groomed themselves, and they no longer liked the plastic cup as much as a live mouse. The animals did better on tests of learning and memory, and the growth of nerve fibers in their brains was controlled. Before treatment, for example, the mice had trouble learning that an underwater platform had been moved. Afterward, they learned its new location.
Now Dr. Sahin is giving a similar drug, everolimus, to autistic children with a tuberous sclerosis gene mutation, asking if it can improve their mental abilities. Richard is among the children. Each child takes the drug or a placebo for six weeks. The study is scheduled to be completed by December 2014.
While Dr. Eng started with cancer gene mutations and discovered a link to autism, Dr. Eichler, of the University of Washington, started with autism and found a connection to cancer genes.
He focused on what he calls “out of the blue autism,” which occurs with no family history, recruiting 209 families with autistic children.
He saw a striking genetic difference. Compared with their parents and normal siblings, the autistic children had two to three times as many mutations that disabled a gene. The mutated genes were often part of a pathway that controls cells growth. At first, the researchers thought the pathway was ubiquitous, and its link to autism was murky.
“We were a bit bummed,” Dr. Eichler said. “Then I said: ‘Wait, some of those genes are cancer genes.’ ”
But he does not yet know whether these children with autism are also at risk for cancer.
“It’s obviously a significant issue,” Dr. Eichler said. “But we need to let the science nail it first.”
The Ewings, whose son is in the autism clinical trial, have learned to live with the tumor threat. For now, their biggest problems are dealing with Richard’s autism.
When Richard’s parents heard about Dr. Sahin’sstudy, they immediately signed him up, though it meant traveling to Boston from Nashville nine times in six months. They had not dared to take their son on planes before, worried that he could not handle the security lines and crowded airports.
But the study was too important to pass up, Mr. Ewing said.
“Traveling with a kid who can’t talk, who has food issues, who is not patient: we hadn’t really done these things,” Mr. Ewing said.
They hope the drug will make a difference.
“We always thought Richard has a lot going on in his brain,” Mrs. Ewing said. “We feel there is a lot of untapped potential.”
For Andrew and Lucy Dabinett’s 9-year-old son, Tommy, whose autism is caused by a PTEN gene mutation, there are no clinical trials as of yet.
Tommy, who lives with his family in Rye, N.Y., has a limited vocabulary, flaps his arms, rocks back and forth, and needs diapers.
When he was 3, a doctor told his parents that he had a PTEN mutation and that in addition to autism, he had a high risk of cancer.
“Of course it is terrifying,” Ms. Dabinett said. “But I already knew there was something terribly wrong with my child. I just needed an answer.”
“Honestly,” she said, “it was a relief to have an answer.”