ESPE Abstracts

Background: X-linked hypophosphatemia (XLH) is a rare genetic disorder of phosphate metabolism caused by mutations in the PHEX gene. XLH patients exhibit short stature and skeletal deformities, which are caused by defective bone mineralization site leading to increased porosity and decreased matrix stiffness. Bone mineral density measurements have been shown to be insensitive to the cumulative bone alterations. The velocity of the first arriving signal (vFAS) ...

Background: In X-linked hypophosphatemia (XLH), abnormally elevated serum fibroblast growth factor 23 (FGF23) results in low renal maximum threshold for phosphate reabsorption (TmP/GFR), low serum phosphorus (Pi), inappropriately normal 1,25-dihydroxyvitamin D (1,25(OH)2D) and development of rachitic deformities.Methods: Up to four s.c. KRN23 doses were given every 28 days to 28 adults with XLH according to a dose-escalation algorithm (0.05&#1...

Background: In X-linked Hypophosphatemia (XLH), abnormally elevated serum Fibroblast Growth Factor 23 (FGF23) results in low renal maximum threshold for phosphate reabsorption (TmP/GFR), low serum phosphorus (Pi), inappropriately normal 1,25-dihydroxyvitamin D (1,25(OH)2D) and development of rachitic deformities.Methods: Up to four SC KRN23 doses were given every 28 days to 28 adults with XLH (26 completed) according to a dose-escalation algorithm (0.05&...

Objectives: In X-linked hypophosphatemia (XLH), abnormally elevated serum Fibroblast growth Factor 23 (FGF23) results in low renal maximum threshold for phosphate reabsorption, low serum phosphorus, inappropriately normal 1,25-dihydroxyvitamin D, and development of rachitic deformities. The effect of KRN23 on health-related quality of life (HRQL) was assessed.Methods: Open-label KRN23 was given s.c. every 28 days up to four doses to 28 adults with XLH (2...

Background: Studies in animal models revealed that brown and white adipocytes derive from different progenitor cells. Molecular characteristics of these cells have not been investigated in detail in humans.Objective and hypotheses: To identify novel markers of human brown adipocyte progenitor cells.Method: Progenitor cells from human paired deep neck and subcutaneous adipose tissue samples were obtained from n=12 subjects ...

Carney complex 1 (CNC, OMIM# 160980) is an autosomal-dominantly inherited complex tumor predisposition syndrome associated with skin pigment abnormalities and neoplasms of heart, endocrine glands and other organs. CNC is caused by heterozygous constitutional loss-of-function variants in the PRKAR1A-gene. PRKAR1A codes for the cAMP-dependent protein kinase type I-alpha regulatory subunit, an enzyme that represents an integral part of protein kinase A (PKA) tha...

Background: Pseudohypoparathyroidism type 1A (PHP1A) and PseudoPHP are caused respectively by maternal and paternal mutations involving those GNAS exons that encode the alpha-subunit of the stimulatory G protein (Gsα). Common to different forms of PHP1B is a loss-of-methylation (LOM) at one or several maternal GNAS exons, which likely reduces Gsα expression in certain tissues. In most autosomal dominant PHP1B variants (AD-PHP1B), LOM is restricted t...

Background: Sporadic pseudohypoparathyroidism type Ib (spor-PHP-Ib) is caused by GNAS methylation alterations with loss of imprinting at the exon A/B differentially methylated region (DMR), without genetic deletions disrupting the STX16 ICR. These patients classically display hormone resistance limited to PTH and TSH with no Albright hereditary osteodistrophy (AHO).Objective and hypotheses: We describe two cases with the same imprinting methylat...

Background: The impact of prematurity on skeletal health later in life is not well elucidated.Objective and hypotheses: In order to address this topic we evaluated bone mass in ex-preterm (PT) and born at term (BT) prepubertal children and potential risk factors for bone health.Method: DXA measures of total body less head and lumbar spine mineral density (TB/L1-L4 BMD, g/cm2 and z-score), bone mineral content (T...

Introduction: Children born small for gestational age (SGA) represent a heterogeneous population, displaying different phenotypes for both growth and metabolic status. Low birth length and/or weight increases the risks for not only growth impairment but also for metabolic derangements (cardiovascular disease, hypertension and type 2 diabetes), the latter with an even amplified risk in children with rapid postnatal weight gain. Variability in metabolic paramete...