The minicolumn is a basic anatomical and physiological element of the mammalian cerebral cortex in the brain, comprising a linear array of pyramidal cell bodies (neurons), their projections that conduct electrochemical information between cells, and accompanying GABAergic interneurons. Postmortem studies of the organization of pyramidal cell arrays in autism have revealed that minicolumns in the brains of autistic patients are narrower. This study will use 58 cases from the Autism Tissue Program (ATP) that have clinical documentation and postmortem magnetic resonance imaging (MRI) data in an attempt to establish a correlation between autopsy and neuroimaging findings in autism. The intent is to develop markers of the condition that can be detected while the patient is alive. Another innovative aspect of the proposal is an attempt to validate current diagnostic screening techniques against autopsy findings by correlating clinical parameters with neuropathological/neuroimaging data.