VPS51 and Intellectual disability: Similarly, whole exome sequencing in two siblings with brain malformations consisting of cerebellar atrophy in the oldest sibling and hypoplastic corpus callosum in the younger sibling affected with delayed psychomotor development, speech deficit, severe intellectual disability, and postnatal microcephaly revealed a homozygous intragenic deletion in VPS51 (c.1419_1421del; p. Phe474del), but no further functional studies were performed [30].