Inclusion criteria:

1. Age ≥4 to <18 years, or ≥18 years at the time of enrollment;

2. Signed ICF for patients ≥18 years, or legal representatives (parents) of patients aged ≥4 to <18 years;

3. Written informed assent (for patients aged ≥14 to <18 years only);

4. No history of HPP treatment with enzyme-replacement therapy;

5. Diagnosis of HPP confirmed by:

   • reduced alkaline phosphatase (ALP) activity relative to age- and sex-specific reference ranges, confirmed by at least two separate measurements, AND
   • the identification of a monoallelic pathogenic, likely pathogenic, or variant of uncertain significance in the ALPL gene on genetic testing.

Exclusion Criteria:

1. Confirmed conditions presenting with clinical features overlapping with HPP, including but not limited to: cerebral palsy, Duchenne muscular dystrophy, limb-girdle muscular dystrophy (Erb-Roth dystrophy), acquired secondary myopathies of various etiologies;
2. Сurrent participation in any clinical study (patients participating in other non interventional studies may be included);
3. Homozygous or compound heterozygous mutation in the ALPL gene
4. In the opinion of the investigator, the patient is not able to return for follow-up visits or obtain required follow-up studies.
5. Pregnant and breastfeeding women.

History of severe allergic reactions to study medication Currently pregnant or breastfeeding Recent participation in another clinical trial within the last 30 days Presence of uncontrolled medical conditions that could affect safety