HEPACAM and megalencephalic leukoencephalopathy with subcortical cysts: Also, megalencephalic leukoencephalopathy with subcortical cysts (MLC; OMIM #604004) is caused by lack of the astrocyte-specific MLC1 protein, either through mutations in the MLC1 gene (73 %) or in the GLIALCAM gene, encoding the MLC1 chaperone GlialCAM (20 %), which ensures proper localization at astrocytic endfeet (Dubey et al 2015).