Endocrine Abstracts

The autoimmune polyendocrinopathy candidiasis ectodermal dystrophy (APECED) syndrome is an autosomal recessive disorder characterized by immune deficiency and the autoimmune destruction of endocrine organs such as the parathyroids, adrenal cortex and ovaries. APECED is caused by biallelic germline mutations of the autoimmune regulator (AIRE) gene on chromosome 21q22.3, which is expressed in thymic medullary epithelial cells and plays a key role ...

Hypoparathyroidism may occur as: a hereditary syndromic disorder (e.g. Autoimmune Polyendocrinopathy Candidiasis Ectodermal Dystrophy (APECED), Hypoparathyroidism Sensorineural Deafness and Renal Disease (HDR), Autosomal Dominant Hypoparathyroidism type 1 (ADH1), or ADH type 2 (ADH2), which are due to mutations of autoimmune regulator (AIRE), GATA binding protein 3 (GATA3), calcium-sensing receptor (CASR) and G-protein sub...

Current treatments, including surgery, medical therapy, radiotherapy, and radionuclide therapy for neuroendocrine tumours of the pancreas (PNETs) and bronchus (BNETs) are often unsatisfactory, leading to a 5-year survival of <50% and 5%, respectively. PNETs and BNETs frequently have mutations in chromatin-remodelling genes and the protein encoded by the multiple endocrine neoplasia type 1 (MEN1) gene, menin. Menin binds the...

Pancreatic neuroendocrine tumours (PNETs) have a lower mutational burden than other tumours, indicating that other mechanisms contribute to tumourigenesis. One such reported mechanism is DNA methylome dysregulation, however, inconsistencies have been observed between gene methylation and protein expression, potentially stemming from the use of standard methylation assessment methods which do not distinguish methylation (5’methylcytosine (5’mC), repressive mark) from ...

The calcium-sensing receptor (CaSR) is a G-protein coupled receptor that predominantly signals via Gαq/11-mediated pathways to regulate extracellular calcium (Ca2+e) homeostasis. Germline Gα11 inactivating and activating mutations cause familial hypocalciuric hypercalcaemia type-2 (FHH2) and autosomal dominant hypocalcaemia type-2 (ADH2), respectively. To date, four FHH2 and six ADH2 mutations have been reported. To identif...

Familial hypocalciuric hypercalcaemia (FHH) is an inherited disorder of calcium homeostasis, which is caused by germline loss-of-function mutations of the calcium-sensing receptor (CaSR) in ˜70% of cases. We report a 22 year old woman who was referred with asymptomatic hypercalcaemia. Biochemical investigations revealed hypercalcaemia on 3 of 4 occasions with adjusted serum calcium ranging from 2.59–2.80 mmol/l (normal range 2.20–2.60 mmol/l). Parathyroid hormon...

Nephrolithiasis is a major clinical and economic health burden. We performed a genome-wide association study in British and Japanese nephrolithiasis populations and identified twenty nephrolithiasis-associated loci, five of which (DGKD, DGKH, WDR72, GPIC1 and BCR) were predicted to influence calcium-sensing receptor (CaSR) signalling. Gain-of-function CaSR-signalling pathway mutations cause enhanced signalling via intracellular calcium ([Ca2+]...

Corticotrophinomas represent >10% of all surgically removed pituitary adenomas, which are the most commonly encountered intracranial neoplasms that are identified in >25% of unselected autopsies and approximately 20% of the population undergoing intracranial imaging. Corticotrophinomas are associated with hypersecretion of adrenocorticotropic hormone (ACTH), which leads to excessive production of glucocorticoids by the adrenal cortex and the resulting hypercortisolemia causes ...

Mutations in cyclin dependent kinase inhibitor 1B (CDKN1B) are associated with multiple endocrine neoplasia type 4 (MEN4), in which patients typically develop parathyroid and anterior pituitary tumours, and occasionally tumours of the pancreas, adrenals, kidneys and reproductive organs. Here, we report a family with a missense mutation of CDKN1B (p.Pro69Leu) that did not have MEN4-associated tumours, but instead had hypomagnesaemia. The proband, presented wit...

Case History: X-linked hypophosphataemia (XLH) manifests as rickets in infancy or childhood, and is caused by mutations of the phosphate-regulating neutral endopeptidase (PHEX) gene, which leads to excess production of the fibroblast growth factor-23 (FGF-23) hormone. We present a case illustrating that mutation of PHEX can also cause hypophosphataemia presenting in adulthood. The proband is a 56-year-old male, who was referred with persistent hypophosphataem...