Mega-Corpus-Callosum Syndrome with Cerebellar Hypoplasia and Cortical Malformations, also known as mccchcm, is related to cerebellar hypoplasia and microcephaly. An important gene associated with Mega-Corpus-Callosum Syndrome with Cerebellar Hypoplasia and Cortical Malformations is MAST1 (Microtubule Associated Serine/Threonine Kinase 1). Affiliated tissues include brain, and related phenotypes are intellectual disability and ventriculomegaly