A Multicenter, Multinational, Observational Morquio A Registry Study (MARS)

Inclusion Criteria: Patients eligible to participate in this Registry must meet all of the following criteria: * Diagnosed with MPS IVA as confirmed by either N-acetylgalactosamine 6-sulfatase (GALNS) enzymatic test or by a diagnostic molecular test * Willing and able to provide written, signed informed consent, or, in the case of patients age \< 18 years, provide written assent (if required) and written informed consent, signed by a legally authorized representative after the nature of the Registry has been explained and prior to performance of any Registry-related procedures * Willing to undergo assessments to establish baseline data or permit Investigator to enter assessment data recorded prior to Registry entry if available in the patient's medical records. Entry assessments may include: demographics, medical history, urinary keratan sulfate level, urinary protein level, immunogenicity testing, vital signs, physical examination, and height and weight Patients eligible to participate in the Registry Substudy for MOR-005 must meet all of the following criteria: * Must have completed the MOR-005 clinical trial * Willing and able to provide written, signed informed consent, or, in the case of patients age \< 18 years, provide written assent (if required) and written informed consent by a legally authorized representative after the nature of the Registry Substudy has been explained and prior to any Registry-related Substudy procedures * Willing to permit Investigator to enter assessment data recorded prior to Registry * Substudy entry if available in the patient's medical records Patients eligible to participate in this Registry Substudy for MOR-007 must meet all of the following criteria: * Must have completed the MOR-007 clinical trial * Willing and able to provide written, signed informed consent, or in the case of patients age \< 18 years, provide written assent (if required) and written informed consent by a legally authorized representative after the nature of the Registry Substudy has been explained, and prior to any Registry-related Substudy procedures * Willing to permit Investigator to enter assessment data recorded prior to Registry Substudy entry if available in the patient's medical records Exclusion Criteria: Patients who meet the following exclusion criterion will not be eligible to participate in the Registry or Registry Substudies: • Patients currently participating in a BMN 110 (elosulfase alfa) clinical trial