This last group of vacuolating LD involves mainly genes expressed in astrocytes such as GFAP (Glial Fibrillary Acidic Protein) and MLC1 (Megalencephalic Leukoencephalopathy with subcortical Cysts 1) or genes ubiquitously expressed as the five EIF2B1-5 genes encoding the general translation eukaryotic initiation factor 2B (eIF2B). The gene discussed is GFAP; the disease is megalencephalic leukoencephalopathy with subcortical cysts.