ESPE Abstracts

Background: Patients affected with PHP1B are characterized by resistance to PTH which binds to the PTH receptor and activate the cAMP/Gsa signaling pathway. Gsa is encoded by GNAS, a locus subjected to genomic imprinting. PHP1B patients present with abnormal methylation at the maternal A/B promoter and, in some cases, at the other promoters (XLas, GNAS-AS1 and NESP55) of the GNAS locus, likely leading to a decreased express...

Background: Disorders related to an impairment in parathyroid hormone (PTH) signaling pathway are historically classified under the term pseudohypoparathyroidism (PHP), that now encompasses rare, related but highly heterogeneous diseases with demonstrated (epi)genetic causes. The actual classification is based on the presence or absence of specific clinical and biochemical signs together with an in vivo response to exogenous PTH and an in vitro assay of Gs&#9...

Background: The effect of profound weight loss following obesity surgery on skeletal microarchitecture and strength in adolescents has not been studied. Obese children are at an increased risk of fracture and childhood obesity leads to reconfiguration of trabecular bone without augmenting bone strength.Objective and hypotheses: To examine the impact of weight loss following 6 months treatment with an intragastric balloon supported by a lifestyle interven...

Background: During early bone formation, mesenchymal stem-cells condense and differentiate into collagen type 2-expressing chondrocytes which form the cartilaginous bone anlagen. This anlage becomes enclosed by the perichondrium. The perichondrium consists of two layers, the inner cambium layer containing chondrocyte- and osteo-precursor cells and the outer fibrous layer important for mechanical and structural support. While the regulation of the growth plate is increasingly w...

Background: Hypophosphatasia (HPP) is a rare, inherited, metabolic disease caused by loss-of-function mutation(s) in the gene encoding tissue nonspecific alkaline phosphatase (TNSALP). Poor skeletal mineralisation, muscle weakness, pain, and accompanying complications characteristic of HPP result in impaired physical function, decreasing ability to perform daily activities, and quality of life. Improvement in physical function is a treatment target, yet established physical ac...

Background: In XLH, high circulating FGF23 causes hypophosphatemia, rickets, and short stature.Objective and hypotheses: To evaluate KRN23 effects on serum phosphate (Pi) level and rickets severity in XLH children in a Phase 2 study.Method: 52 XLH children (ages 5–12 years, ≤Tanner 2) received KRN23 subcutaneously biweekly (Q2W) or monthly (Q4W). Serum Pi was measured at 2-week intervals. KRN23 dose was titrated (maximum...