MSD, also known as Austin disease and mucosulfatidosis, is a rare LSD caused by mutations in the SUMF1 gene, resulting in an accumulation of sulphatides, sulphated glycosaminoglycans, sphingolipids and steroid sulphates (Austin, 1973; Cosma et al., 2003; Dierks et al., 2003). This evidence concerns the gene SUMF1 and mucosulfatidosis.