MPS III B. Sanfilippo B disease.
Incidence
1:24,000 for all the types. AR inheritance. It is a alpha-N-acetylglucosaminidase deficiency.
Clinical Characteristics
Severe mental retardation, mild skeletal changes, corneal clouding questionable. There is very little coarsening features in Sanfilippo disease. Minimal dwarfism. No cardiac abnormalities. Progressive neurological deterioration with seizures & athetosis Mild bone changes. No visceral involvement. Before age 10 years, ambulation is no longer possible and patients are confined to bed. The course is inexorably progressive and most patients die before age 20 yrs.
Precipitants
no
Provocation Tests
no
Diagnostic Procedures
EB(F), Urine metabolic screen with Berry test. MPS (HS) in urine. Frequently the spot test may be false negative.