The mucopolysaccaridoses

The mucopolysaccaridoses are a collection of rare genetic conditions where there is a defect in lysosomal storage causing an accumulation of glycosaminoglycans. There are seven different forms of mucopolysaccaridosis (MPS), each with a different enzymatic mutation and thus each form has similar but separate clinical features. There are multiple effects of glycosaminoglycan deposition including musculoskeletal manifestations such as joint problems and growth arrests. Common treatments of the orthopaedic complications include hip arthroplasty, cervical spine surgery and epiphyseal stapling to correct genu valgum. Presently, the only curative treatment for MPS is haematopoietic stem cell transplantation. Enzyme replacement therapy is a future target for all forms of MPS and a range of therapies are currently in development.