[Early response to idursulfase in a 31-year old male patient with Hunter syndrome]

The response to Enzyme Replacement Therapy (ERT) in Hunter syndrome (MPS II) occurs early in most of the patients after its initiation and continues during the first 12-18 months. However, almost all the patients with MPS II have severe forms of the disease and death occurs prematurely. More than 90% of subjects die before 25 years, and only a minority will survive after the age of 30. There is very limited information on early response to ERT among adult patients with Hunter's syndrome. We report the case of a 31 year-old male with MPS II, with a remarkably severe joint disability, but mild cognitive impairment, who was treated with idursulfase for six months. The pattern of response observed, was similar to what can be expected in younger patients. The amelioration in joint mobility observed in this case suggests that older patients with advanced articular involvement may benefit from idursulfase, even when therapy is started in later stages of the disease.