Carnegie Mellon Statistician Roeder Finds Genetic Risk for Autism

Press Release: Using New Statistical Tools, Carnegie Mellon's Kathryn Roeder Finds Genetic Risk for Autism Stems Mostly From Common Genes -Carnegie Mellon News - Carnegie Mellon University

I've written before about spontaneous, de novo, genetic variation and autism. The theory, which I consider favored by current research, is that genetics represent the primary factor contributing to autistic traits. Now, with statistical modeling, researchers find a likely correlation between genetics and autism.

If mild autistic traits are within inherited genetics, this suggests autistics are somewhere along the "spectrum" based on which additional variations occur.

"Within a given family, the mutations could be a critical determinant that leads to the manifestation of ASD in a particular family member," said Joseph Buxbaum, the study's first author and professor of psychiatry, neuroscience, genetics and genomic sciences at the Icahn School of Medicine at Mount Sinai (ISMMS). "The family may have common variation that puts it at risk, but if there is also a 'de novo' mutation on top of that, it could push an individual over the edge. So for many families, the interplay between common and spontaneous genetic factors could be the underlying genetic architecture of the disorder."

After you have the predisposition for an ASD, the expression of autism varies based on the de novo variation. Copy number regulation (CNR) is a common source of genetic change. Duplication of genes is an amazing event, and it is astounding more errors don't occur with serious side effects. Term pregnancies are something of a statistical miracle.

Now that the genetic architecture is better understood, the researchers are identifying specific genetic risk factors detected in the sample, such as deletions and duplications of genetic material and spontaneous mutations. The researchers said even though such rare spontaneous mutations accounted for only a small fraction of autism risk, the potentially large effects of these glitches make them important clues to understanding the molecular underpinnings of the disorder.

Random variation rarely is caused by environmental (external) factors. But, most people outside science mistakenly assume genetic means inherited. In fact, the genetics that shape us most are often little more than random variation without a specific cause.

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