Sanfilippo syndrome

The most common disorder of mucopolysaccharide metabolism, a syndrome in which the onset of clinical abnormalities is between the ages of 2 and 6 with mild coarsening of the facial features (but normal clear corneas), mild stiffening of the joints, slowing of growth, and intellectual deterioration resulting in severe mental retardation.

On a biochemical level, Sanfilippo syndrome is characterized by the excess excretion of heparin sulfate alone in the urine and the accumulation of mucopolysaccharides in the central nervous system and other tissues.

On the genetic level, there are 4 types of Sanfilippo syndrome (types A, B, C, and D), each due to deficiency of a different enzyme.

All 4 types are inherited in an autosomal recessive manner and result in an identical clinical syndrome.

Also known as mucopolysaccharidosis Type III (MPS III).