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)

The sustained effects of biochemical screening to increase both apparent incidence and age at diagnosis indicate that, without screening, most patients with primary hyperparathyroidism would would never be diagnosed. This suggests that asymptomatic patients discovered as a result of screening have a nonprogressive form of the disease, with adverse health effects that are few or nontraditional, for which treatment policies validated only in symptomatic patients may be inappropriate. Accordingly, in 1975 we formulated criteria for withholding surgical treatment from such patients. Of 174 who were eligible for study over a 10 year period, clinical, biochemical, and densitometric assessment was repeated after at least 1 year (mean 52 months) in 106 patients who did not differ in any initial characteristic from 68 patients in whom follow-up was inadequate. There was no change in symptoms, no disease complications, and no change in any index of hormone secretion or disease severity. In 30 patients, individual regression slopes against time were not significant for any serum measurement. In these patients the disease appeared to have stopped progressing by the time the diagnosis was made, most likely because of cessation of tumor growth. There was a significant deficit in appendicular cortical bone at the time of diagnosis but no further acceleration of bone loss thereafter. In an earlier study, surgical cure was followed by a modest increase in forearm bone density for the first 6 months, but even after 3 years only about 20% of the deficit was corrected. The deficit in bone density is smaller in the spine than in the forearm and is not accompanied by any increase in vertebral fracture risk.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Asymptomatic primary hyperparathyroidism discovered by multichannel biochemical screening: clinical course and considerations bearing on the need for surgical intervention. 176 76

Primary hyperparathyroidism is a chronic, multi-system disease due to an overproduction of PTH from adenoma, hyperplasia or carcinoma of the parathyroid. Classical disease type classification consisted of bone type, kidney type and latent or chemical type. Though a longer course is usually associated with more severe involvement of especially the skeletal system and larger tumor size, the progression of the disease is not always uniform. Rapid tumor growth may be associated with shorter course and more extensive involvement. The role of PRAD1, a DNA sequence near the PTH gene on chromosome 11 possibly related to tumor growth, should further be investigated with reference to the disease types and courses of the disease.
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PMID:[Primary hyperparathyroidism. Concept, classification and symptomatology]. 775 72

Since the classic description by Fuller Albright in the 1940s, primary hyperparathyroidism has evolved from a disease with classic signs and symptoms to a disease in search of symptoms! Since that time, two major events have occurred. First, in the United States, United Kingdom, and in most European countries, there has been a steady rise in the apparent incidence of the disease. Second, there has been a dramatic shift in the pattern of presentation. A majority of patients with primary hyperparathyroidism in countries with multichannel screening panels are asymptomatic. Skeletal and renal complications are uncommon, and osteitis fibrosa is rare. In contrast, the clinical presentation of primary hyperparathyroidism has changed very little in other regions such as the East, the Middle East, and some parts of the southern hemisphere over the same period of observation. Accordingly, we assessed the influence of vitamin D and calcium nutrition on the disease expression and parathyroid tumor growth in patients with primary hyperparathyroidism from different parts of the world. Between 1945 and 1950, both the prevalence of osteitis fibrosa and parathyroid tumor weight declined dramatically in the United States, coinciding with fortification of milk with vitamin D. In contrast, osteitis fibrosa and parathyroid tumor weight changed very little in parts of the world where vitamin D depletion is endemic. Furthermore, for a comparable degree of vitamin D depletion, Asian Indians have significantly larger tumors compared with Americans (3.95 +/- 2.23 vs. 0.66 +/- 2.84 g; p < 0.001). Within the United States, blacks have larger tumors compared with whites (0.78 +/- 2.87 vs. 0.58 +/- 2.78 g; p < 0.01). However, the slopes of regression between serum 25-hydroxyvitamin D, the best index of vitamin D nutrition, and parathyroid tumor weight, the best available index of parathyroid growth, were not significantly different between Asian Indians, whites, and blacks. We conclude that vitamin D and calcium nutrition of the population affect both the clinical expression and parathyroid tumor growth in patients with primary hyperparathyroidism. It will be of interest to see if the pattern of presentation of primary hyperparathyroidism changes when better nutritional policies are implemented in developing countries.
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PMID:Role of vitamin D and calcium nutrition in disease expression and parathyroid tumor growth in primary hyperparathyroidism: a global perspective. 1241 81

Primary hyperparathyroidism is among the most common causes of hypercalcemia. However, ingestion of medication, including hydrochlorathiazide, lithium, and foscarnet, excessive vitamin A ingestion, endocrinopathies such as hyperthyroidism, adrenal insufficiency, and acromegaly, abnormal nutrient intake such as parenteral nutrition in preterm infants and milk-alkali syndrome, and prolonged immobilization have all been associated with hypercalcemia. The most common cause of nonparathyroid hypercalcemia is neoplasia. Hypercalcemia is generally due to the secretion of parathyroid hormone (PTH)-related peptide (PTHrP) by a wide variety of nonmetastatic solid tumors, including squamous cell tumors but also hematologic tumors. PTHrP, although encoded by a distinct gene, shares amino acid sequence homology with PTH in the amino-terminal domain, which allows it to cross-react at a common G protein receptor, the type 1 PTH/PTHrP receptor (PTHR1), resulting in similar skeletal effects and effects on calcium and phosphorus metabolism. Increased PTHrP action with hypercalcemia may be seen in the benign disease Jansen's metaphyseal chondrodysplasia due to a gain-of-function mutation in PTHR1. Another humoral factor, 1,25-dihyroxyvitamin D [1,25(OH)2D] may be produced by lymphomas, but also by benign granulomatous disorders and may also cause hypercalcemia when its metabolism is genetically impaired. Vitamin D intoxication may cause hypercalcemia due to overproduction of the metabolite, 25 hydroxyvitamin D, apparently in the absence of conversion to 1,25(OH)2D. Malignancies metastatic to bone or arising in bone (such as multiple myeloma) may produce a variety of growth factors and cytokines, in addition to PTHrP, which can contribute to tumor growth as well as osteolysis and hypercalcemia.
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PMID:Nonparathyroid Hypercalcemia. 3064 26

Hyperparathyroidism-jaw tumor (HPT-JT) syndrome is an autosomal dominant disorder characterized by parathyroid tumors in association with fibro-osseous jaw tumors and uterine and renal lesions. HPT-JT syndrome is caused by germline mutations of the cell division cycle 73 (CDC73) gene that encodes the parafibromin, a 531-amino acid protein with antiproliferative activity. Primary hyperparathyroidism is the main finding of HPT-JT syndrome, usually caused by a single-gland parathyroid involvement (80% of cases), at variance with other variants of hereditary hyperparathyroidism, in which a multiglandular involvement is more frequent. Moreover, parathyroid carcinoma may occur in approximately 20% of cases. Surgery is the treatment of choice for primary hyperparathyroidism, but the extent of surgery remains controversial, varying between bilateral neck and focused exploration, with subtotal or limited parathyroidectomy. Recently, more limited approaches and parathyroid excisions have been suggested in order to decrease the risk of permanent hypoparathyroidism, the main surgical morbidity following more extensive surgical approaches. Ossifying fibromas of the mandible or maxilla may present only in a minority of cases and, even if benign, they should be surgically treated to avoid tumor growth and subsequent functional limitations. Benign and malignant uterine involvement (including leiomyomas, endometrial hyperplasia, adenomyosis, multiple adenomyomatous polyps, and adenosarcomas) is the second most common clinical feature of the syndrome, affecting more than 50% of CDC73-carrier women. Genetic testing should be performed in all family members of affected individuals, in young patients undergoing surgery for primary hyperparathyroidism, or in presence of other associated tumors, allowing early diagnosis and prompt treatment with more tailored surgery. Moreover, CDC73 mutation carriers should be also periodically screened for primary hyperparathyroidism and the other associated tumors. The present review was aimed to summarize the main clinical features of HPT-JT syndrome, focusing on genetic screening and surgical treatment, and to revise the available literature.
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PMID:Clinical Features, Treatment, and Surveillance of Hyperparathyroidism-Jaw Tumor Syndrome: An Up-to-Date and Review of the Literature. 3192 90