Endocrine Abstracts

The hypoparathyroidism, deafness and renal dysplasia (HDR) syndrome is an autosomal dominant disorder that is due to mutations of the dual zinc-finger transcription factor, GATA3. The C-terminal zinc finger (ZF2) is crucial for DNA binding, whilst the N-terminal finger (ZF1) stabilizes the DNA binding by ZF2 and interacts with other multi-type zinc finger proteins, referred to as Friends of GATA (FOG), which modulate GATA3 function. The majority of GATA3 mutations causing HDR ...

The hypoparathyroidism, deafness and renal dysplasia (HDR) syndrome is an autosomal dominant disorder that is due to a haploinsufficiency of the zinc-finger transcription factor, GATA3 (Nature (2000) 406: 419) whose gene is located on chromosome 10p15. In order to further characterise GATA3 abnormalities we have investigated 6 HDR patients for GATA3 mutations. Leukocyte DNA samples from the 6 probands and an unrelated normal individual were used with 9 pairs of oligonucleotide...

Autoimmune polyendocrinopathy type 1 (APS1) is an autosomal recessive disorder characterised by hypoparathyroidism, adrenocortical failure, and mucocutaneous candidiasis. The gene causing APS1 is the autoimmune regulator (AIRE-1) gene, which maps to 21q22.3 and consists of 14 exons. The AIRE-1 protein, comprising of 545 amino acids, contains two PHD zinc-finger motifs, a proline rich region and four LXXLL motifs, consistent with its role as a transcription factor. Over 25 diff...

X-linked recessive hypoparathyroidism (XLHPT), due to congenital parathyroid agenesis, has been reported in two related kindreds from Missouri, USA. Affected individuals, who are males, suffer from epilepsy due to hypocalcaemia during infancy, whilst the females are normocalcaemic. Studies have mapped XLHPT to chromosome Xq27 and defined a 1.5 Mbp interval flanked centromerically by Factor IX and telomerically by DXS984. DNA sequence analysis of 4 candidate genes (proto-dbl, A...

(This poster is based on OC3)...

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...

The hyperparathyroidism-jaw tumour (HPT-JT) syndrome, an autosomal dominant disorder, is characterised by the occurrence of parathyroid tumours, often carcinomas, and ossifying fibromata of the jaw. The HPT-JT gene, referred to as HRPT2, is located on chromosome 1q25 and consists of 17 exons that encode a 531 amino-acid protein designated parafibromin. To explore the role of HRPT2 in parathyroid tumourigenesis, we generated two mouse models that comprised a conve...