Megalencephalic Leukoencephalopathy with Subcortical Cysts 2b, also known as megalencephalic leukoencephalopathy with subcortical cysts 2b, remitting, with or without mental retardation, is related to megalencephalic leukoencephalopathy with subcortical cysts 2b, remitting, with or without impaired intellectual development and achilles bursitis. An important gene associated with Megalencephalic Leukoencephalopathy with Subcortical Cysts 2b is HEPACAM (Hepatic And Glial Cell Adhesion Molecule). Related phenotypes are macrocephaly and megalencephaly