Endocrine Abstracts

Familial juvenile hyperuricaemic nephropathy (FJHN), an autosomal dominant disorder characterised by raised serum urate, reduced fractional excretion of uric acid (FEUA), a urine concentrating defect, and progressive renal failure, is caused by mutations in the UMOD gene, encoding uromodulin (Tamm–Horsfall glycoprotein). The FJHN-causing UMOD mutations are missense mutations (>90%) or inframe deletions (<10%), and none result in prematurely truncated...

Familial hypocalciuric hypercalcaemia (FHH) comprises three genetic variants: FHH types 1 and 2 are due to mutations of the calcium-sensing receptor (CaSR) and G-protein subunit alpha-11, whereas, FHH type 3 (FHH3) is caused by heterozygous mutations affecting the Arg15 residue (Arg15Cys, Arg15His, Arg15Leu) of the adaptor-related protein complex 2-sigma subunit (AP2S1), which regulates CaSR endocytosis. FHH is usually associated with mild hypercalcaemia, normal parathyroid ho...

Autosomal dominant hypocalcaemia type 1 (ADH1) is a systemic disorder of calcium homeostasis caused by gain-of-function mutations of the calcium-sensing receptor (CaSR). ADH1 may lead to symptomatic hypocalcaemia, inappropriately low parathyroid hormone (PTH) concentrations and hypercalciuria. Active vitamin D metabolites are the mainstay of treatment for symptomatic ADH1 patients, however their use predisposes to nephrocalcinosis, nephrolithiasis and renal impairment. Calcily...

The G-protein coupled calcium-sensing-receptor (CaSR) regulates calcium homeostasis and inactivating mutations result in familial hypocalciuric hypercalcaemia (FHH), whilst activating mutations result in autosomal dominant hypocalcaemia with hypercalciuria (ADHH). Allosteric CaSR modulators consist of: calcimimetics, which activate the CaSR e.g. Cinacalcet, that is used to treat the hypercalcaemia of chronic renal failure and metastatic parathyroid carcinoma; and calcilytics e...

(This poster is based on OC24)...

Multiple Endocrine Neoplasia type 1 (MEN1) is an autosomal dominant disorder characterised by the combined occurrence of tumours of the parathyroids, pancreas and pituitary. The MEN1 gene, which is located on chromosome 11q13 and encodes a 610 amino acid protein (menin), belongs to the class of tumour suppressors. To investigate the role of menin in tumour suppression, three different mouse models have been generated through targeted disruption of the Men1 gene. ...

Inbred laboratory mice are widely used to generate, by homologous recombination, transgenic and chemical mutagenesis routes, genetic models of human disease. However, physiological studies of such models are hampered by the lack of normal ranges for serum and urinary biochemistry, particularly in relation to acclimatisation following placement in metabolic cages. To establish such values, we investigated urinary and serum parameters in forty, 24–30 week-old C3H/HeH, BALB/...

Heterozygous mutations of GATA3, a dual zinc-finger transcription factor, cause the hypoparathyroidism, deafness and renal dysplasia (HDR) syndrome. To study the role of GATA3 in parathyroid function we have investigated Gata3+/− mice for hypoparathyroidism. Gata3+/− and Gata3+/+ mice were challenged at weaning with a diet low in calcium (0.001%) and vitamin D (0.0 IU/g). The low calcium-vitamin D diet led to a ...

Transient receptor potential cation channel, subfamily Vanilloid, member 5 (TRPV5) is a member of the TRP superfamily. TRPV5, which functions as a tetramer, is localized to apical membranes of distal convoluted tubules (DCT) and connecting tubules (CNT) of the kidney, and is involved in vitamin D-regulated calcium reabsorption. Mice with a targeted deletion of Trpv5 (Trpv5−/−) develop severe hypercalciuria, compensatory hyperabsorption of dietary ...

The Hypoparathyroidism, Deafness and Renal dysplasia (HDR) syndrome is an autosomal dominant disorder caused by mutations in the dual zinc-finger transcription factor GATA-3. Gata3 heterozygous (+/−) knockout mice develop deafness, while Gata3 homozygous (−/−) mice, which are embryonically lethal at 11.5 to 12.5 days post-coitum (dpc), develop renal hypoplasia. The parathyroids have not been studied, and we therefore investigated these mice for ...