Endocrine Abstracts

Familial hypocalciuric hypercalcaemia type-3 (FHH3) is caused by loss-of-function mutations of the sigma subunit of adaptor protein-2 (AP2), a ubiquitously expressed heterotetrameric protein with a fundamental role in endocytosis of transmembrane proteins. FHH3-associated AP2σ mutations impair internalisation of calcium-sensing receptor (CaSR) giving rise to FHH. CaSR predominantly signals via Gαq/11 leading to intracellular calcium release, and activation...

Familial hypocalciuric hypercalcaemia (FHH) is an autosomal dominant disorder characterised by hypercalcaemia and inappropriately low renal calcium excretion. FHH can be classified into three types: FHH1, caused by calcium-sensing receptor (CaSR) loss-of-function mutations, accounting for >65% of cases; FHH2, due to loss-of-function mutations of the G-protein α11 subunit (Gα11); and FHH3, resulting from loss-of-function mutations in the adap...

Adaptor protein-2 (AP2) is a heterotetramer of α, β, μ, and σ subunits that is pivotal in clathrin-mediated endocytosis and facilitates internalisation of plasma membrane constituents such as the calcium-sensing receptor (CaSR). AP2 σ subunit (AP2σ) missense mutations (Arg15Cys, Arg15His and Arg15Leu) result in familial hypocalciuric hypercalcaemia type 3 (FHH3) and decrease the sensitivity of CaSR-expressing cells to changes in extracellular calc...

The prolactin receptor (PRLR) is a type-I cytokine receptor that plays critical roles in mammary gland development, lactation and glucose metabolism, and PRLR mutations have been associated with breast cancer and familial hyperprolactinaemia. The PRLR signals via Janus kinase-2-signal transducer and activator of transcription-5 (JAK2-STAT5) or phosphoinositide 3-kinase-Akt (PI3K-Akt) pathways to mediate changes in transcription, differentiation and proliferation, and we hypoth...

Multiple endocrine neoplasia type 1 (MEN1) is an autosomal dominant disorder characterised by the occurrence of parathyroid, pancreatic and pituitary tumours, and is due to mutations of the MEN1 gene, which encodes menin. We have investigated identical twins with MEN1, one of whom developed primary hyperparathyroidism (PHPT) and a prolactinoma that caused pubertal arrest, and the other had PHPT only. DNA sequence analysis of the MEN1 coding region had not ide...

Aims: Our aim was to explore predictive factors for the pleiotropic responses to exenatide during the first 12 weeks of therapy, and associations between these responses.Methods: This was an observational study based on patients (n=83) with type 2 diabetes mellitus (T2D) in whom exenatide had been added to existing oral hypoglycaemic therapy. Exenatide was administered subcutaneously (5 mcg bd for the first month, 10 mcg bd thereafter). Data colle...

Familial hypocalciuric hypercalcaemia types 1, 2, and 3 (FHH1, FHH2, and FHH3) are caused by loss-of-function mutations of the calcium-sensing receptor (CaSR), G-protein subunit α11 (Gα11) and adaptor protein 2 sigma subunit (AP2σ), respectively; whilst autosomal dominant hypocalcaemia types 1 and 2 (ADH1 and ADH2) are due to gain-of-function mutations of CaSR and Gα11, respectively. We therefore hypothesised that gain-of-function AP2σ mutations may re...

Familial hypocalciuric hypercalcaemia (FHH) comprises three types: FHH1, FHH2, and FHH3, which are due to mutations of the calcium-sensing receptor (CaSR), G-protein α 11 subunit (Gα11), and adaptor protein-2 sigma subunit (AP2σ), respectively. The aims of this study were: to assess for genotype–phenotype correlations among the three reported FHH3-causing AP2σ mutations, which all involve the Arg15 residue, and comprise Arg15Cys, Arg15His, and Arg15Leu...

Familial hypocalciuric hypercalcaemia (FHH) is an autosomal dominant disorder characterized by hypercalcaemia and inappropriately low urinary calcium excretion, and is occasionally associated with acute pancreatitis. FHH can be classified into three types: FHH type 1, caused by loss-of-function mutations of the calcium-sensing receptor (CaSR), which accounts for >65% of cases; FHH type 2, due to loss-of-function mutations of the G-protein α 11 subunit (Gα11), of ...