advancing research in basic sciences and mathematics
We and our collaborators have recently reported the discovery that 1% or more of cases of autism spectrum disorder (ASD) are caused by the spontaneous loss of a section of DNA from chromosome 16. This stretch of DNA contains 25 genes and is flanked on each side by a repeated DNA stretch containing 3 more genes, one copy of which is also lost. In each case, the mutation event that resulted in loss of the DNA was newly occurring as there was no evidence of it in either parent, indicating that when it occurs it is a strong cause of ASD. Interestingly, we found that an extra copy of this DNA segment is also a risk factor for autism, but in this case it occurs most frequently as a mutation inherited from a parent and may not result in ASD as consistently as the loss of the same DNA. The discovery of this discrete mutation in the DNA as a frequent recurrent cause of ASD provides the opportunity to characterize a specific genetic defect that could be extremely informative, providing new clues to the biochemical alterations that lead to ASD. The findings so far support the idea that one gene in the region causes autism because having only one of the two parental copies is just not sufficient to support normal brain development. Consequently, our goal is to capitalize on very recent advances in the ability to analyze gene sequences and gene expression to identify the specific gene that matters among these 28 candidates. We also plan to use cutting-edge methods of reprogramming human skin cells to make pluripotent stem cells that can be converted in the lab into nerve cells, where we can directly study the effects of this and other ASD genes.
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