Secondary skeletal involvement in Sanfilippo syndrome.

BACKGROUND

Sanfilippo syndrome, or mucopolysaccharidosis (MPS) type III, is a rare lysosomal storage disease, resulting from errors in the catabolism of heparan sulphate.

AIM

To evaluate bone turnover and bone mineral density (BMD) in MPS type III patients.

DESIGN

Clinical and observational study.

METHODS

We evaluated serum markers of bone formation or resorption, and measured BMD using dual-energy X-ray absorptiometry (DEXA), in three patients with MPS type III.

RESULTS

Serum vitamin D were low, and BMDs greatly reduced at lumbar and femoral sites, indicating the possibility of osteoporosis and osteomalacia.

DISCUSSION

These skeletal effects probably result from nutritional deficiencies and inability to walk, rather than from the genetic defect itself. Secondary skeletal involvement in patients with MPS type III may represent a considerable cause of morbidity, and requires interventions to reduce the risk of pathological fractures.