Endocrine Abstracts

Dent's disease is an X-linked renal tubular disorder characterised by low molecular weight proteinuria, hypercalciuria, and nephrolithiasis. The disease is caused by inactivating mutations of a renal-specific chloride channel, hCLC-5, that belongs to the family of mammalian voltage-gated chloride channels (CLCs). Heterologous expression of wild-type CLC-5 in Xenopus oocytes results in chloride (Cl-) conductance, which is markedly reduced or abolished by the m...

SEMDs are a heterogeneous group of skeletal disorders characterised by defective growth and modelling of the spine and long bones. Genetic defects in two inherited SEMDs have been identified and these involve abnormalities of the collagen type II gene located on chromosome 12q12-q13.2, and an ATP sulfurylase/APS kinase gene located on 10q23-34. These are not the cause of the Missouri variant (SEMDMO), which occurs as an autosomal dominant trait in a unique four-gene...

Hereditary multiple exostosis (HME) is an autosomal dominant disorder characterised by the development of benign cartilage-capped tumours, located at the juxtaepiphyseal regions of long bones. Patients suffer from short stature and skeletal deformities and may occasionally develop chondrosarcomas or osteosarcomas.HME is a genetically heterogeneous disorder and three loci referred to as EXT1, EXT2 and EXT3 have been mapped to chromosomes 8q24.1, 11p11-12...

Calcium sensing receptor (CaSR) mutations may result in either hypocalciuric hypercalcaemia or hypocalcaemic hypercalciuria due to a loss or gain of function, respectively. It has also been postulated that some gain of function CaSR mutations may result in idiopathic (i.e. normocalcaemic) hypercalciuria (IH). We reasoned that such CaSR mutations would lead to an early onset of IH and have sought for them in 12 unrelated children who were normocalcaemic and developed IH nephrol...

The calcium sensing receptor (CaSR) plays a central role in altering the secretion of parathyroid hormone (PTH) in response to alterations in extracellular calcium, and four studies have reported an association between CaSR polymorphisms and serum Ca 2+, serum PTH, and bone mineral density (BMD). However, two other studies have failed to detect such associations. We have therefore undertaken studies to investigate the Ala986Ser, Arg990Gly, and Gln1011Glu CaSR polymo...

Multiple endocrine neoplasia type 1 (MEN1) is an autosomal dominant disorder characterised by parathyroid, anterior pituitary and pancreatic islet tumours. Primary hyperparathyroidism is the first clinical manifestation in >85% of patients, although in some patients pancreatic and pituitary tumours may precede the occurrence of primary hyperparathyroidism. The earliest occurrence of MEN1-tumours has been reported at the age of 5 years following which the age-related penetr...