CHD8 Gene and Autism

Dozens of genes have been found to be correlated with autism. However, according to James P. Noonan, an associate professor of genetics, ecology and evolutionary biology at the Kavli Institute for Neuroscience at Yale University, one of these genes, CHD8, has been found to be a “master regulator in the developing human brain” and to “control the expression of many other genes.” The function of CHD8 is thought to be to regulate gene expression by “modifying the way DNA interacts with histones, proteins present in the nucleus of every cell that wind long strands of DNA.” People who have “a loss-of-function mutation in this gene, which inactivates the corresponding protein, are very likely to have an autism diagnosis.” Noonan’s study was published in March in the journal Nature Communications.

In the study, Noonan and his fellow researchers looked at developing brains of people and mice as well as neuronal stem cells. They found that CHD8 bound to thousands of sites in the brains of the humans and mice as well as the stem cells. Next, they reviewed previous genetic studies and found that “autism-associated genes were more likely to be targeted by CHD8 than expected by chance.” Finally, they looked at whether CHD8 had a regulatory effect on these genes associated with autism. The researchers looked to accomplish this goal by “reducing the expression of the CHD8 gene in cultured human neuronal stem cells and explored what, if any, gene expression levels changed.” The result of this reduced gene expression was the impaired regulation of many of the targeted genes but “autism risk genes were most strongly affected.” Mr. Noonan believes that as a result of this type of research, answers to what “biological pathways and developmental processes that are affected in autism” will be developed.

Source: March 10, 2015