The Effect of Monoallelic Variants in the ALPL Gene on the Natural Course of Hypophosphatasia in Russia

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.