Inclusion Criteria: * Diagnosis of Mucopolysaccharidosis type I Hurler-Scheie or Scheie syndrome. * Age ≥ 18 years at time of study registration. * Creatinine clearance, calculated or measured directly, that is \>60ml/min/1.73m2. * Ejection fraction ≥ 40% by echocardiogram. * Must commit to traveling to the study site for the necessary follow-up evaluations. * Must agree to stay \<45-minute drive from the study site for a minimum of 5 days after cell infusion. Exclusion Criteria: * Known familial inherited cancer syndrome. Suspected cases will be investigated, per the physicians discretion, using relevant genetic tests to determine presence of germline mutations. * History of B cell related cancer, EBV lymphoproliferative disease or autoimmune disorders. * Evidence of active graft-vs-host disease. * Underwent a previous hematopoietic stem cell transplant (HSCT). * Requirement for systemic immune suppression. * Requirement for continuous supplemental oxygen. * Any medical condition likely to interfere with assessment of safety or efficacy of the study treatment. * In the investigator's judgement, the subject is unlikely to complete all protocol-required study visits or procedures, including follow up visits, or comply with the study requirements for participation. Other protocol defined inclusion/exclusion criteria may apply.