Mutations in CASK are associated with mental retardation as well as structural defects in the brain such as pontocerebellar hypoplasia, Ohtahara syndrome [6], FG syndrome with corpus callosum agenesis [6], [7], [8], [9], [10], tetralogy of Fallot [11], and autism spectrum disorders [12], [13]. The gene discussed is CASK; the disease is FG syndrome.