Three adult siblings with mucopolysaccharidosis type II (Hunter syndrome): A report on clinical heterogeneity and 12 months of therapy with idursulfase

Abstract

Mucopolysaccharidosis type II (MPS II–Hunter syndrome) is a rare X-linked recessive disease oflysosomal glycosaminoglycan metabolism leading to asystemic storage disorder. We report three adult brothers(aged 46–52 years) with attenuated Hunter syndrome after12 months of enzyme replacement therapy with idursulfase.Before enzyme replacement therapy, each had serious complicationsof their disease: in addition to all requiring urgentcervical spinal canal decompressions in middle age, onerequired emergency aortic and mitral valve surgery, anotherhad stage IV airways disease, and the third had acute glaucomaresulting in unilateral blindness. One brother discontinuedtherapy after 12 months. The other two brothersreported subjective improvements in energy and exercisetolerance.