Growing evidence points to a role for the immune system in autism. One possibility is that certain antibodies made by a pregnant mother can target her developing fetus in such a way as to increase autism risk. By this hypothesis, the antibodies are autoantibodies, which mistake the developing fetus as a foreign pathogen. Research from Dr. Van de Water's lab has found evidence for maternal autoantibodies that target fetal brain tissue in mothers of children with autism. Dr. Van de Water's fellow will further explore the role of these antibodies in autism and will begin to characterize the specific targets of these antibodies. First, the protein targets of antibodies from mothers of multiple children with autism multiplex will be compared to those from mothers of one child with autism simplex. This will reveal whether these are different types of autism that are associated with different maternal autoantibodies. Second, the location of the targeted proteins in the brain will be determined via immunohistochemistry. This technique will use the autoantibodies as markers; once bound to their targeted proteins in the brain, they will be visualized to reveal where in the brain the targeted proteins reside.