SANFILIPPO

Rare autosomal recessive lysosomal storage disease caused by a deficiency in one of the enzymes needed to break down the glycosaminoglycan heparan sulfate (which is found in the extra-cellular matrix and on cell surface glycoproteins). Manifests in young children. Affected infants are apparently normal, although some mild facial dysmorphism may be noticeable. The stiff joints, hirsuteness and coarse hair typical of other mucopolysaccharidoses are usually not present until late in the disease. After an initial symptom-free interval, patients usually present with a slowing of developmental and/or behavioral problems, followed by progressive intellectual decline resulting in severe dementia and progressive motor disease.