We screened whole exome sequencing data from a total of 789 exomes (418 autism cases and 371 controls) that were sequenced at the Broad Institute (as described above) as part of a case-control study by the ARRA Autism Sequencing Consortium. Recessive mutations (homozygous and compound heterozygous) were counted in cases and in controls and a Fisher's exact test was used to determine whether the number of mutations in cases was significantly different than the number in controls. Samples in this study are of European ancestry from the AGRE collection, the Autism Sequencing Consortium (ASC), and the National Institute of Mental Health (NIMH).
