Enzyme replacement therapy for mucopolysaccharidosis VI (Maroteaux-Lamy syndrome): experience in Hong Kong.

Mucopolysaccharidosis VI (MPS VI; Maroteaux-Lamy syndrome) is a lysosomal storage disease caused by deficient activity of the enzyme N-acetylgalactosamine 4-sulfatase (arylsulfatase B). The stepwise degradation of the glycosaminoglycan (GAG) dermatan sulfate is impaired and partially degraded GAG accumulates intracellularly in lysosomes, causing a chronic progressive disorder with multi-organ dysfunction.1 This disease is a heterogeneous condition. The rapidly advancing form is characterised by growth failure, skeletal and joint deformities, coarse facial features, upper airway obstruction, and recurrent ear infections. Other clinical manifestations include hepatomegaly, cardiopulmonary disease, blindness, hydrocephalus and spinal cord compression. Affected individuals often become wheelchair bound or bedridden and die in the second decade or third decade from infections, complications related to surgical procedures or cardiopulmonary diseases. Individuals with the slowly progressive form may live longer. In both forms, the disease inevitably leads to significant functional impairment and reduced lifespan, although intelligence is usually preserved.2