ESPE Abstracts

Hypophosphatasia (HPP) is a rare, inherited metabolic disease caused by deficient activity of tissue non-specific alkaline phosphatase (TNSALP). In children, HPP has a heterogeneous clinical presentation, frequently with nonspecific musculoskeletal and systemic manifestations, often leading to misdiagnoses and substantial delays in diagnosis. Data from 323 children with confirmed HPP diagnosis (aged <18 years, ALP activity below the reference range and/or ALPL mut...

Background: Hypophosphatasia (HPP) is an inherited multisystem disorder predominantly affecting the mineralization of bones and teeth. HPP is caused by pathogenic variants in ALPL, which encodes tissue non-specific alkaline phosphatase. A major challenge in diagnosing HPP is interpreting variants in ALPL classified as variants of uncertain significance (VUS) according to ACMG/AMP criteria, creating uncertainty in patients and treating physicians resulting in d...