HHEX and metachromatic leukodystrophy: The level of other lysosomal enzymes, such as total beta-hexosaminidase (Hex) and beta-galactosidase, from SV40t MLD patient (ASA-D355V/c.495+1C>A) and control (ASA-WT) cells were not significantly different from the levels obtained from the original and corresponding primary cell lines (Fig.1E).