Post-approval Clinical Study of Asfotase Alfa Treatment for Patients With Hypophosphatasia (HPP) in Japan

Inclusion Criteria: 1. Patient or parent (or legal guardian) must provide written informed consent prior to the performance of any study-related procedures and must be willing to comply with study procedures. Where appropriate and required by local regulations, patient assent for participation must also be obtained. 2. Patient has completed the investigator-initiated clinical study (HPPJEAP-01) protocol for asfotase alfa Exclusion Criteria: 1. Patient has a documented form of rickets caused by a condition other than HPP, including, but not limited to, rickets caused by 25(OH) vitamin D deficiency 2. Patient has serum calcium and/or phosphorus levels below the normal range 3. Patient is pregnant or lactating 4. Patient received treatment with bisphosphonates within 2 years prior to the Screening visit 5. Patient has a documented sensitivity to any of the components of asfotase alfa 6. Patient is currently enrolled in any other program or clinical study involving an investigational new drug, device, or treatment for HPP (eg, bone marrow transplantation) 7. Patient has clinically significant other disease in the opinion of the Investigator, defined as any other non HPP-related condition for which the patient is considered medically unstable.