SUMF1 and metachromatic leukodystrophy: Further, multiple sulfatase deficiency (MSD), a similar lysosomal storage – related leukodystrophy with significant CNS involvement arising from autosomal recessive mutation in the sulfatase-modifying factor 1 (SUMF1) encoding gene, causes profound reduction in downstream sulfatase activities, including the sulfatases associated with other LSDs like MLD and various mucopolysaccharidosis (MPS) (Fraldi et al., 2007).