The disclosure features methods for identifying the health state of patients having hypophosphatasia (HPP). The health state of the patient, once identified, can be used to, e.g., assign a treatment regimen featuring the administration of a soluble alkaline phosphatase (sALP) to the patient, to monitor the efficacy of the treatment regimen, and/or to modify the treatment regimen. The methods also include assessing the transition of a patient with HPP from one health state to another, e.g., after completion of a treatment regimen that includes administering an sALP.
