Musculoskeletal manifestations of mucopolysaccharidoses.

The mucopolysaccharidoses (MPSs) are a heterogeneous group of inherited metabolic disorders caused by enzyme deficiencies that lead to progressive lysosomal storage of glycosaminoglycans. Musculoskeletal manifestations are common across all forms of MPS and are often apparent early in the disease course. Diagnostic delays occur frequently in these patients, especially those with more attenuated forms of disease. Treatments for many types of MPS are now available; however, they are most effective if started early before the development of irreversible damage. Some manifestations such as stiffness and joint contractures may mimic other conditions such as inflammatory arthritis, which may cause further delays. Rheumatologists and other specialists should be aware of the musculoskeletal manifestations of MPS so that diagnostic delays can be avoided and appropriate management initiated.