Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0221002 (primary hyperparathyroidism)
 4,921 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Recently, patients with asymptomatic primary hyperparathyroidism (aPHPT) are on the increase. When serum Ca, P and intact PTH are determined frequently, it is not difficult to diagnose of aPHPT, even when serum alkaline phosphatase activity is increased in some postmenopausal women. However, the criteria for operation for aPHPT is difficult, because the natural course of aPHPT is unknown, particularly in terms of bone mineral density. Since bone mineral density is genetically regulated by polymorphism of vitamin D receptor (Nature 1994), the analysis of restriction fragment length polymorphism of the vitamin D receptor may be useful as one of criteria for operation in patients with aPHPT in the near future.
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PMID:[Differential diagnosis between osteoporosis and asymptomatic primary hyperparathyroidism]. 796 79

Polymorphisms in the vitamin D receptor (VDR) gene have been hypothezised to interfere with VDR expression. VDR alleles (Bb, Aa and Tt) were examined in 254 Caucasian patients with sporadic primary hyperparathyroidism (spHPT, n = 206), HPT of multiple endocrine neoplasia type 1 (MEN-1; n = 17), and HPT of uremia (n = 31). In comparison to age- and sex-matched controls, the b, a and T alleles were overrepresented in 100 menopausal females with spHPT (p = 0.006-0.0004), equivalent to an odds ratio of 2.6-3.4 for spHPT in homozygotes for the b, a and, T alleles. The association between VDR genotypes and spHPT was restricted to female patients and those with parathyroid adenoma (p = 0.0006-0.0001), whereas HPT of MEN 1 and uremia seemed unrelated to the VDR polymorphisms (p = 0.26-0.96). The results suggest that the VDR alleles b, a, and T are novel risk factors in the essentially uncharacterized pathogenesis of spHPT.
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PMID:Vitamin D receptor alleles b, a, and T: risk factors for sporadic primary hyperparathyroidism (HPT) but not HPT of uremia or MEN 1. 907 Feb 72

Clonal analysis has shown that in renal hyperparathyroidism (2-HPT), parathyroid glands initially grow diffusely and polyclonally after which the foci of nodular hyperplasia are transformed to monoclonal neoplasia. There is a great deal of information about genetic abnormalities contributing to the tumourigenesis of parathyroid neoplasia in primary hyperparathyroidism. It is speculated that allelic loss of the MEN1 suppressor gene and overexpression of cyclin D1 induced by rearrangement of the parathyroid hormone gene may be the major genetic abnormality in sporadic parathyroid adenoma but not in 2-HPT. The pathogenesis of 2-HPT, abnormality of the Ca2+-sensing receptor (CaR) gene and the vitamin D receptor gene may possibly contribute to parathyroid tumourigenesis in 2-HPT. However, this is not yet clear and heterogeneous and multiple genetic abnormalities may be responsible for the progression of secondary parathyroid hyperplasia.
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PMID:Mechanism of parathyroid tumourigenesis in uraemia. 1004 55

Vitamin D regulates parathyroid cell proliferation and secretion of PTH. Increased prevalence of the polymorphic vitamin D receptor (VDR) alleles b, a, and T has been reported in sporadic primary hyperparathyroidism (PHPT), suggesting that these genetic variants may predispose to the disease. Recently, another polymorphism in the VDR gene was related to bone mineral density, and this VDR-FokI polymorphism causes different lengths of the VDR, implying possible functional consequences. The VDR-FokI polymorphism was studied in 182 postmenopausal women with sporadic PHPT and in matched controls. No significant differences in distribution of the VDR-FokI genotypes could be detected between the groups, although there was a tendency toward overrepresentation of the F allele in the PHPT patients (P = 0.05). There were no significant associations with age, serum calcium, serum PTH, bone mineral density, or parathyroid tumor weight. The VDR genotypes were unrelated to VDR and PTH messenger ribonucleic acid levels in the parathyroid adenomas of 42 PHPT patients. In 23 PHPT patients, the Ca2+-PTH set-points were determined in vivo and were unrelated to the VDR alleles. We suggest that the VDR-FokI polymorphism has at most a minor pathogenic importance in the development of PHPT.
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PMID:The vitamin D receptor (VDR) start codon polymorphism in primary hyperparathyroidism and parathyroid VDR messenger ribonucleic acid levels. 1032 1

The role of vitamin D receptor (VDR) gene polymorphisms in the pathogenesis of hyperparathyroidism is uncertain. Controversial results have been reported. The aim of this study was to explore the relevance of BsmI VDR gene polymorphism in patients with primary hyperparathyroidism (PHPT) due to adenomas. For this purpose, 36 postmenopausal patients with PHPT, mean age 64 years, were compared with a normal age-matched female population (n = 81). BsmI polymorphism distribution in PHPT group was as follows: Bb 50% (18/36); BB 22% (8/36); bb 28% (10/36). In the control group, the distribution was Bb 49% (40/81); BB 16% (13/81); bb 35% (28/81). No statistical differences were found between the two groups. In the PHPT group, no statistical associations were found between different allelic distribution and age, creatinine, hematocrit, phosphorus, alkaline phosphatase (ALP), total calcium, serum parathyroid hormone (PTH), or gland weight. By contrast, levels of serum calcium and iPTH values positively correlated with the PT weight (r = 0.421 and 0.599, respectively, P = 0.0001). Our data suggest that at least in this group, BsmI VDR gene polymorphism appears to be of minor relevance in clinical presentation and possibly, tumorigenesis in PHPT due to adenomas.
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PMID:Lack of relationship between BsmI vitamin D receptor polymorphism and primary hyperparathyroidism in a Spanish female population. 1044 53

Primary hyperparathyroidism is the third most frequent endocrine disorder. The condition required for diagnosis is inappropriately elevated secretion of parathyroid hormone (PTH) with respect to calcemia. Most often, the disease is due to a parathyroid adenoma, i.e. a monoclonal benign parathyroid tumor, less often to a parathyroid hyperplasia. The main tumorogenic mechanisms currently proposed are a DNA rearrangement in the PTH locus (transposition of the PTH promoter upstream to Cyclin D1/PRAD 1 gene) and a mutation of the gene responsible for multiple endocrine neoplasia type I. The clinical presentation has strikingly evolved towards a milder, asymptomatic form, frequently diagnosed on systematic screenings. Though the mechanism of hypercalcemia is better understood, several hypothesis are still being considered about the regulation of tumoral PTH secretion: the role of the expression of calcium-receptor in parathyroid gland cells, vitamin D receptor and estrogen receptor polymorphisms, etc. Surgery is still advised for symptomatic forms of the disease, either because of a bone involvement, or because of an evolutive nephrolithiasis. In the near future, the new calcium-receptor agonists could be a relevant therapeutic approach.
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PMID:[Primary hyperparathyroidism]. 1111 7

Susceptibility to Graves' disease (GD), which is determined by environmental and genetic factors, is conferred by genes in the human leukocyte antigen (HLA) and genes unlinked to HLA, including the CTLA-4 gene. We recently described the association of GD with the vitamin D receptor (VDR) exon 2 initiation codon (VDR-FOK:I) polymorphism. An association of some VDR genotypes with osteoporosis, primary hyperparathyroidism, and some autoimmune diseases, such as insulin-dependent diabetes mellitus and multiple sclerosis, has been reported. We investigated the distribution of VDR gene polymorphism in 180 Japanese patients with GD (48 males and 132 females) and 195 controls (67 males and 128 females). A VDR allelic polymorphism was assessed by BSM:I endonuclease restriction after specific PCR amplification. Genotypic polymorphism was clearly defined as BB (no restriction site on both alleles), bb (restriction site on both alleles), or Bb (heterozygous). The distribution of genotype frequencies differed between patients with GD and controls (chi(2) = 7.53; 2 degrees of freedom; P: = 0.023). The relative risk conferred by at least 1 B allele (BB or Bb) was 1.5. We also found an association between VDR-APA:I polymorphism and GD. No relation was detected between this polymorphism and the VDR-FOK:I polymorphism in the patients. The present results support the association of the VDR gene with GD in Japanese by showing that the VDR gene could be a non-HLA-linked gene predisposing an individual to GD. The role of the VDR gene polymorphism should be further studied in other populations, and the distribution of other polymorphisms, such as the polyadenylase polymorphism further down the VDR 3'-untranslated region, should be studied in terms of GD susceptibility.
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PMID:Vitamin D receptor gene polymorphism is associated with Graves' disease in the Japanese population. 1113 21

Primary hyperparathyroidism (pHPT), generally caused by a monoclonal parathyroid adenoma, is a common endocrinopathy. Until recently, the genesis of the disease was poorly understood but during the past decade the molecular pathology of parathyroid tumor development has begun to be unveiled. This review summarizes recent advances in our understanding of genetic predisposition to pHPT, and the role of vitamin D receptor gene (VDR) variants in development of the disease. It has been shown that the multiple endocrine neoplasia tumor suppressor gene (MEN1) is mutated in parathyroid adenomas, and overexpression of the cyclin D1 oncogene [PRAD1 (parathyroid adenoma 1)] seems to contribute to parathyroid tumorigenesis. Several familial hyperparathyroid disorders have been studied, and the identification and characterization of the disease-causing genes have contributed to our understanding of parathyroid physiology and pathophysiology.
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PMID:Molecular pathology of parathyroid tumors. 1116 22

Primary hyperparathyroidism (pHPT) is commonly seen in postmenopausal women. Along with the clinical characterisation of the disease, studies of molecular genetics have contributed to increased understanding of the etiology of pHPT. Genetic association studies have revealed that certain vitamin D receptor polymorphisms relate to the development of sporadic pHPT. A new type of familial pHPT was recently discovered. Studies of parathyroid adenomas have demonstrated that the tumor suppressor gene MEN1 and the oncogene cyclinD1 are of importance for the tumorigenesis.
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PMID:[Primary hyperparathyroidism is common among postmenopausal women. Identification of genetic risk factors can contribute to individualized treatment]. 1140 99

In this study, we report an 84-year-old female proband in a Japanese family with familial hypocalciuric hypercalcemia (FHH) caused by an R648stop mutation in the extracellular calcium-sensing receptor (CaR) gene. At the age of 71 years, she presented with hypercalcemia (11.4 mg/dl), hypocalciuria (Cca/Ccr = 0.003), hypermagnesemia (2.9 mg/dl), and a high-serum parathyroid hormone (PTH) level (midregion PTH, 3225 [160-520] pg/ml). At the age of 74 years, a family screening was carried out and revealed a total of 9 hypercalcemic individuals (all intact PTH values <62 pg/dl) among 17 family members tested, thus, being diagnosed as FHH. Two and one-half of three clearly enlarged parathyroid glands were resected, because persistently high PTH levels (intact PTH, 292 pg/ml; midregion PTH, 5225 pg/ml) and the presence of a markedly enlarged parathyroid gland by several imaging modalities (ultrasonography, computed tomography [CT], magnetic resonance imaging [MRI], and subtraction scintigraphy) suggested coexistent primary hyperparathyroidism (pHPT); however, hypercalcemia persisted postoperatively. Histological and immunohistochemical examination revealed that the resected parathyroid glands showed lipohyperplasia as well as normally expressed Ki67, vitamin D receptor (VDR), and the CaR. Sequence analysis disclosed that the proband and all affected family members had a heterozygous nonsense (R648stop) mutation in the CaR gene. This mutation is located in the first intracellular loop; thus, it would be predicted to produce a truncated CaR having only one transmembrane domain (TMD) and lacking its remaining TMDs, intracellular loops, and C-terminal tail. Western analysis of biotinylated HEK293 cells transiently transfected with this mutant receptor showed cell surface expression of the truncated protein at a level comparable with that of the wild-type CaR. The mutant receptor, however, exhibited no increase in intracellular free calcium concentration (Ca2+i) when exposed to high extracellular calcium concentrations (Ca2+o). The proband's clinical course was complicated because of associated renal tubular acidosis (RTA) and nephrotic syndrome. However, it was unclear whether their association affected the development of elevated serum PTH and parathyroid gland enlargement. This report is the first to show that an R648stop CaR mutation yields a truncated receptor that is expressed on the cell surface but is devoid of biological activity, resulting in FHH.
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PMID:Familial hypocalciuric hypercalcemia caused by an R648stop mutation in the calcium-sensing receptor gene. 1246 11


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