Genetics May Be Behind Autism

While there are many who still cling to the possibility that autism is the result of too many vaccinations in the first two years of life or mercury exposure or some other environmental input, scientists at Harvard University have discovered several genes that may provide insight into why intensive education regimes appear to work with some children.

All the genes seem to be part of a network involved in a basic foundation of learning -- how neurons respond to new experiences by forming connections between each other, called synapses.

In the first year or two of life -- when autism symptoms appear _ synapses rapidly form and mature, and unnecessary ones are "pruned" back. In other words, a baby's brain is literally being shaped by its first experiences so that it is structurally able to perform learning and other functions of later life.

"This paper points to problems specifically in the way that experience sculpts the developing brain," explained Dr. Thomas Insel, director of the National Institute of Mental Health, which helped fund the work.

Some earlier research had pointed to the same underlying problem, so these newly found genes "join a growing list to suggest that autism is a synaptic disorder," he said.

If that sounds discouraging, here's the good news: The missing DNA didn't always translate into missing genes. Instead what usually was missing were the on/off switches for these autism-related genes. Essentially, some genes were asleep instead of doing their synapse work.
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"I find that hopeful" because "there are ways that are being discovered to activate genes," Walsh said. "This might be an unanticipated way of developing therapies in the long term for autism: Identifying these kids where all the right genes are present, just not turned on in the right way."