has material basis in autosomal recessive disease megalencephalic leukoencephalopathy with subcortical cysts megalencephalic leukoencephalopathy with subcortical cysts 2A DOID:0080318 MIM:613925 A megalencephalic leukoencephalopathy with subcortical cysts characterized by infantile-onset macrocephaly and later onset of motor deterioration, with ataxia and spasticity, seizures, cognitive decline of variable severity, white matter abnormalities, including swelling of the cerebral white matter and subcortical cysts that has_material_basis_in homozygous or compound heterozygous mutation in the HEPACAM gene on chromosome 11q24. disease_ontology autosomal recessive inheritance