A Study of JR-171 in Patients With Mucopolysaccharidosis I

Inclusion Criteria: * A patient aged 18 years or older in Part 1 or any age in Part 2, at the time of informed consent * A patient from whom written informed consent can be obtained. If the patient is aged under 18 years (20 years in case of Japan) at the time of assent or willingness to participate in the study cannot be confirmed due to MPS I-related intellectual disability, informed permission from the patient's legally acceptable representative (e.g. his/her parents or guardians) need to be obtained instead of his/her consent. Even in this case, written informed consent or assent should be obtained from the patient, wherever possible * A patient diagnosed with MPS I based on any one of the following criteria: * Activity of IDUA enzyme below 10% of lower reference level in leucocytes or cultured skin fibroblasts, AND increased age-related urinary levels of GAGs (before enzyme replacement therapy) * Activity of IDUA enzyme below 10% of lower reference level in leucocytes or cultured skin fibroblasts, AND presence of one pathogenic mutation in each of the alleles of the IDUA gene * Increased age-related urinary levels of GAGs (before enzyme replacement therapy), AND presence of one pathogenic mutation in each of the alleles of the IDUA gene * A patient diagnosed as having no or mild MPS I-related intellectual disability (able to report their own subjective symptoms) by the principal investigator or subinvestigator (Part 1 only) * A patient who has received laronidase contin…