The effect of monoallelic variants in the ALPL gene on the natural course of hypophosphatasia in Russia - ATLANTIS

Inclusion Criteria

• 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.