Among the many mysteries that befuddle autism researchers: why the disorder affects boys four times more often than girls. But in new findings reported online today by the journal Molecular Psychiatry, researchers say they have found a genetic clue that may help explain the disparity.
The newly discovered autism-risk gene, identified by authors as CACNA1G, is more common in boys than in girls (why that's so is still not clear), and the authors suggest it plays a role in boys' increased risk of the developmental disorder. CACNA1G, which sits on chromosome 17, amid other genes that have been previously linked to autism, is responsible for regulating the flow of calcium into and out of cells. Nerve cells in the brain rely on calcium to become activated, and research suggests that imbalances in the mineral can result in the overstimulation of neural connections and create developmental problems, such as autism and even epilepsy, which is also a common feature of autism. (See six tips for traveling with an autistic child.)
"Our current theories about autism suggest that the disorder is related to overexcitability at nerve endings," says Geri Dawson, chief science officer of Autism Speaks, an advocacy group that provided the genetic data used by the study's authors. "It's interesting to see that the gene they identified appears to modulate excitability of neurons."
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