The primary rationale for amending the protocol for Study MOR-007 (Amendment 1) is to include BMN 110 stopping criteria. In addition, Amendment 1 contains other changes as follows: 1. The use of antihistamines and antipyretics prior to study drug infusion was further clarified to address that all patients will be pretreated with an age-appropriate dose of antihistamine medication and antipyretic medications at the discretion of the Investigator due to the risk of paradoxical CNS stimulation or seizures in neonates. 2. The age restriction for the PedsQLTM instrument has been removed, as new parent reports for infants from 0–12 months and 13–24 months have been recently introduced.

The primary changes for protocol MOR-007 (Amendment 2): 1. Changed Visit window from +/- 4 days to +/-3 days. 2. Added collection of genotype data as part of a patient's medical history. 3. Added collection of the patient's age at the time of Morquio A diagnosis as part of patient's medical history 4. Added measurement of head circumference in all patients at the same time points as other anthropometric measurements 5. Added collection of O2 saturation via pulse oximetry to vital sign collection at all visits 6. Clarified that urinary GAG will be tested in duplicate. 7. Clarified which body parts will be evaluated by dual-emission x-ray absorptiometry (DXA). Where feasible both whole body scan and a lumbar spine DXA scan will be performed. If only one scan will be performed the Investigator should ensure that the same type of scan is performed at both the screening and Week 52 visits. Although the actual scan performed is a whole body scan, for accurate calculation of bone density in this age group the head will be excluded from the analysis. Removed allowance to use a DXA scan at screening taken within the prior 3 months 8. Clarified the inclusion criterion that patients must be <5 years old at the date of the first study-drug infusion 9. Specified that anthropometric measurements will be collected in duplicate (with a 3rd of the first two measurements are outside the specified error range) 10. Added type IIA Collagen N-Propeptide (PIIANP) as an assessment at Baseline, Week 25 and Week 52 11. Added collection of an additional blood sample for plasma KS at Baseline and at weeks 4, 8 and 52 12. Collection of dental samples 13. Updated language on the dilution of BMN110 for children with different weights 14. Clarification that radiologic, echocardiogram, electrocardiogram and magnetic resonance imaging collected and reviewed centrally 15. A post-infusion phone contact was added 16. Change in name and contact of Medical Monitor

The primary changes for protocol MOR-007 (Amendment 3): 1. A long-term extension phase has been added to the existing protocol. An interim analysis and interim CSR will be performed when the last patient in has reached Week 52. 2. Language surrounding the use of antihistamines and antipyretics has been modified. 3. The second urine collection on the day of infusion has been removed. 4. The statement that 100% of the data will be source document verified has been removed.