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...

Objectives: HPP is a multisystem disorder caused by ALPL variants that lead to ALP deficiency and excessive inorganic pyrophosphate, which inhibits mineralization of bones and teeth. A range of symptoms is associated with HPP inherited in an autosomal dominant manner that can manifest at any stage of life, making diagnosis difficult. The traditional method of classifying HPP into different types based on the onset of symptoms (prenatal benign, perinat...