The Long-term Safety Study of Idursulfase-beta in Hunter Syndrome(Mucopolysaccharidosis II) Patients

Inclusion Criteria: * Patients who have a diagnosis of Hunter syndrome(Mucopolysaccharidosis II). * Patients who are administered idurasulfase-beta or willing to be administered idurasulfase-beta. * Patient's parent(s), or patient's legal guardian must have given voluntary written consent to participate in the study. Exclusion Criteria: * Patients who have participated in any other blind clinical trials. * Patient who cannot be tracked about safety. * Patients who are judged disqualified to participate clinical trials by investigator for other causes.