Two independent lines of evidence indicate that the maternal immune system and a functional genetic variant contribute to autism spectrum disorder (ASD) risk. Here, the Van De Water lab will partner with scientists at Vanderbilt University to examine whether these two seemingly unrelated contributions may converge to define a unique ASD susceptibility. Preliminary evidence collected by the Van De Water lab indicates an association between the Mesenchymal epithelial transition factor (MET) gene 'C' type, which reduces MET protein expression, and the presence of specific maternal anti-fetal brain autoantibodies. This relationship suggests that this as a pathway for production of the maternal autoantibodies, leading to a gene x environment interaction underlying ASD susceptibility. The next line of experiments will examine the relationship in an even larger sample and assess the functional effect of the MET gene polymorphism on immune cell activity as well as further examine the impact of environmental toxins (including ethyl mercury) on the gene expression-dependent function of maternal immune cells.