An autosomal recessive disorder that has features of both mucopolysaccharidoses (Hunter, Sanfilippo A, Morquio, Maroteaux-Lamy), X-linked ichthyosis and metachromatic leukodystrophy. This disorder affects 12 sulfatase enzymes (Ex. arylsulfatase, steroid sulfatase, heparan sulfatase, N-acetylglucosamine-6-sulfatase). Multiple different enzymes may be deficient and residual enzyme activities may vary between patients. As such patients present at varying ages and with varying presentations. The most frequent form occurs in early childhood but rare neonatal and juvenile forms exist.
1. Neonatal MSD: Severe mucopolysaccharidosis
2. Late infantile MSD: Late onset metachromatic leukodystrophy
3. Juvenile MSD
On imaging patients have brain atrophy, white matter disease manifested by multiple T2 hyperintensities, and occasionally enlarged perivascular spaces. They may resemble patients with metachromatic leukodystrophy