Megalencephalic Leukoencephalopathy with Subcortical Cysts 3, also known as leukoencephalopathy, megalencephalic, with subcortical cysts, type 3, is related to megalencephalic leukoencephalopathy with subcortical cysts 1. An important gene associated with Megalencephalic Leukoencephalopathy with Subcortical Cysts 3 is GPRC5B (G Protein-Coupled Receptor Class C Group 5 Member B). Affiliated tissues include brain and skeletal muscle.