ESPE Abstracts

Introduction: The melanocortin 4 receptor (MC4R) is a G protein coupled receptor (GPCR) and plays a pivotal role in the central regulation of body weight in the hypothalamus. In the context of the leptin-melanocortin signaling pathway, the MC4R is activated by the endogenous ligands a- and b-MSH (melanocyte-stimulating hormone). This leads to the feeling of satiety and to a reduction in food intake. Mutations within the genes leptin, leptin receptor (LEPR), pr...

Here we identified and characterized a heterozygous tandem duplication at the ASIP (agouti-signaling protein) gene locus causing ubiquitous, ectopic ASIP expression in a female index patient with extreme childhood obesity. In patient-derived adipose tissue samples, we observed pronounced differentiation of stroma-vascular fraction (SVF) cells into adipocytes in the patient compared to normal control cells. We further found reduced mitochondrial maximum respir...

Background: Patients with rare monogenic obesity caused by biallelic variants of genes such as proopiomelanocortin (POMC; including variants in PCSK1) or leptin receptor (LEPR) deficiency, experience hyperphagia (a pathologic, insatiable hunger) and early-onset, severe obesity. This suggests potential increased risk over time of obesity-related comorbidities, including metabolic syndrome, a cluster of conditions associated with increased risk of cardiovascular...

Background: Transgender adolescents may be treated with gender affirming hormone therapy (GAHT) consisting of gonadotropin-releasing hormone agonists (GnRHa) and cross-sex hormones. Limited data are available regarding the metabolic effects of GAHT in adolescence.Objective: To evaluate the lipid profiles and HbA1c in transgender adolescents after one year of cross-hormone treatment.Patients...

Introduction: XLH is caused by mutations in PHEX leading to increased FGF23 levels, phosphate wasting, and impaired endogenous calcitriol synthesis. Affected patients present with rickets and diminished growth velocity during childhood, and osteomalacia and short stature in adulthood. Adult height is linked with health within and across generations suggesting that adult height may be a potential tool for monitoring health conditions, e.g., XLH.<p ...

Background: Isolated aldosterone synthase deficiency is a rare autosomal recessive disorder caused by pathogenic variants in CYP11B2. To date, more than forty different pathogenic variants in the CYP11B2 gene causing isolated aldosterone synthase deficiency have been identified. We report on a novel pathogenic CYP11B2 variant.Case report: The second child (male) of consanguineous, healthy parents, presented shortly after...

Background/Aim: X-linked hypophosphatemia (XLH) is a rare disease caused by mutations in PHEX, leading to elevated FGF23 levels, hypophosphatemia and chronic renal phosphate wasting. Burosumab is a monoclonal antibody against anti-FGF23, which has been recently approved for treatment of XLH. Beyond clinical trials, little is known about its efficacy/safety in clinical practice which is the aim of study.Patients/Methods: ...

Background: Studying patients with rare Mendelian diabetes has highlighted molecular mechanisms regulating β-cell pathophysiology. Previous, experimental studies have shown that Class IIa histone deacetylases (HDAC4, 5, 7, and 9) modulate mammalian pancreatic endocrine cell differentiation, function and finally glucose homeostasis.Methods: We performed exome sequencing in one adolescent boy with non-autoimmune di...

Objective: This project aims to evaluate the effect of two isotopically labelled internal standards on the quantification of 17OHP by liquid chromatography-tandem mass spectrometry (LC-MS/MS) and gas chromatography-tandem mass spectrometry (GC-MS/MS) as an orthogonal technique.Methods: Three LC-MS/MS and one GC-MS/MS laboratories, spanning four countries worldwide, who routinely measure serum17OHP, compared two internal ...

Background/Aim: X-linked hypophosphatemia (XLH) is a rare disease caused by inactivating mutations in the phosphate-regulating endopeptidase homolog X-linked (PHEX) gene, characterized by chronic hypophosphatemia. XLH children present with progressive skeletal deformities (leg bowing, waddling gait, poor growth and disproportional short stature), dental abscesses, and craniosynostosis. Most affected children have been treated so far with multiple dail...