ESPE Abstracts

Introduction: Hypophosphatasia (HPP) is the rare, inherited, metabolic disease with broad-ranging severity caused by inactivating mutation(s) in the tissue-nonspecific alkaline phosphatase (TNSALP) gene. In the childhood form of HPP, there are mineralization defects of the bones and teeth, often with impaired physical function, muscle weakness, and decreased growth. We previously reported sustained radiographic improvement in rickets compared to historical controls in 5–1...

Background: Hypophosphatasia (HPP) is the rare inherited metabolic disorder resulting from loss-of-function mutation(s) in the tissue-nonspecific alkaline phosphatase (TNSALP) gene. TNSALP deficiency can cause a spectrum of complications in children including premature deciduous tooth loss, rickets, poor growth, and compromised physical function. We previously reported that children, 5–12 years old, with HPP and treated with asfotase alfa, a recombinant bone-targeted huma...

Hypophosphatasia (HPP) is a rare, inherited, systemic disease caused by mutation(s) of the ALPL gene encoding tissue-nonspecific alkaline phosphatase (ALP), resulting in deficient ALP activity. Asfotase alfa is an enzyme replacement therapy approved for treatment of patients with pediatric-onset HPP. The global HPP Registry is an observational, prospective, multinational study (NCT02306720; EUPAS13514) established to collect real world clinical data from patients of a...

Background: Hypophosphatasia (HPP) is a rare, inherited metabolic disease characterised by bone mineralisation defects and osteomalacia, and systemic manifestations, including seizures, respiratory insufficiency, muscle weakness, nephrocalcinosis, and pain. The biochemical hallmark of HPP is low serum alkaline phosphatase activity, resulting from loss-of-function mutations in the gene encoding tissue non-specific alkaline phosphatase. HPP presents a broad spectrum of disease s...

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: Referrals to pediatric endocrine clinics for short stature are common. Height velocity (HV) is an essential component of the evaluation of short stature as growth deceleration often reflects an underlying pediatric endocrine diagnosis (PED). Access to previous measurements facilitates prompt calculation of HV.Objective and hypotheses: To determine availability of previous measurements at time of referral for short stature, to characterize PED...

Background: PAPP-A2 is a metalloproteinase that specifically cleaves IGFBPs 3 and 5. Papp-a2 knock-out (KO) mice show a reduction in body size and skeletal abnormalities.Objective and hypotheses: Our objective is to report two affected families from Spain and USA. The Spanish family presents a homozygous frameshift mutation in exon 3 of the PAPP-A2 gene (c.1927_ 1928insAT, p.D643fs25X) resulting in a premature stop codon, with 2 of 4 si...

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...