It is possible that an aberrant immune response in mothers during vulnerable, critical periods of neurodevelopment could produce neuronal injury in the fetal or neonatal brain and produce long-term neurological dysfunction characteristic of autism. In this study, researchers will examine several quantifiable biological signatures of immune cells in blood from mothers of children with autism, including RNA levels of immune molecules, functional assays of white blood cells, and the presence of antibodies directed to fetal-brain proteins. Findings from this study could help in identifying a subgroup of mothers of children with autism who share a specific immune-related phenotype. This may improve the ability of researchers to detect genes associated with this subgroup. The identification of biological signatures of specific autism-related immune abnormalities may shed light on the cause(s) of autism in this subgroup and potentially lead to prevention or treatment strategies prior to or during pregnancy.