GLB1 mutations in GM1 gangliosidosis, HEXA mutations in Tay-Sachs disease, and HEXB mutations in Sandhoff disease were found in all, of which GLB1 c.622C>T (p.R208C) in P108 was a common mutation for patients with GM1 gangliosidosis[67]. Here, HEXA is linked to Sandhoff disease.