Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0020438 (hypercalciuria)
 2,502 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The relatives of 25 index patients with primary parathyroid hyperplasia were tested for hypercalcemia. At least 13 of these patients had one or more first degree relatives with hypercalcemia. Two familial syndromes each with autosomal dominant transmission were recognized. Two index patients were part of large kindreds categorized as having familial hypocalciuric hypercalcemia (FHH). Manifestations of multiple endocrine neoplasia type I were present in the kindreds of at least four other index patients (FMEN I). In seven other kindreds there were too few affected members to allow definitive classification. Differences between manifestations of FHH and FMEN I were described. Among offspring of affected persons in kindreds with FHH, as distinct from FMEN I, the prevalence of hypercalcemia approached the theoretic maximum of 50 per cent during the first two decades. In FHH, nephrolithiasis and peptic disease were unusual; moderate hypercalcemia occurred without hypercalciuria; and subtotal parathyroidectomy did not abolish hypercalcemia. Concentrations of peptide hormones other than parathyroid hormone (PTH) were normal in those with FHH; in FMEN I high concentrations of glucagon in plasma were found in five of six patients tested, and high concentrations of gastrin were found in three of 12 patients. Hypergastrinemia generally accompanied obvious peptic disease. Distinction of the two conditions is important since patients with FHH may not benefit from subtotal parathyroidectomy, but they generally have a better clinical prognosis than do patients with FMEN I.
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PMID:Family studies in patients with primary parathyroid hyperplasia. 87 Nov 27

Four patients with milk-alkali syndrome (MAS) presented with many of the characteristics of primary hyperparathyroidism including hypercalcemia, low or normal serum phosphorus levels, normal or increased urinary calcium levels, and inappropriately high or elevated serum parathyroid hormone levels. These laboratory findings differ from those classically described in MAS, i.e., hypercalcemia without hypercalciuria and a normal or high plasma phosphate level. Because the serum calcium level failed to return to normal after two weeks of hydration and a low calcium diet, and because of the inability to distinguish this syndrome from primary hyperparathyroidism, two of the four patients underwent neck exploration. Four normal parathyroid glands were histologically proven in each, and at autopsy in a third patient, there was no evidence of parathyroid hyperplasia or adenoma. Hypercalcemia eventually resolved in all patients with a low-calcium diet for as long as six months. Of the several features of MAS, hypercalcemia, alkalosis in the presence of azotemia, a history of increased calcium and alkali intake, and a response to dietary calcium restriction are helpful in differentiating this syndrome from primary hyperparathyroidism. Laboratory tests in patients with MAS may be confusing and the return to normocalcemia in response to a calcium deficient diet may be delayed.
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PMID:Milk alkali syndrome. Does it exist and can it be differentiated from primary hyperparathyroidism? 683 Mar 49

Among 52 patients with recurrent renal calcium stones submitted for neck exploration 12 had adenomas, 23 hyperplasia and only 17 histologically normal parathyroid glands. These patients were selected for surgery despite a normal mean value of the total serum calcium concentration because they had, in most cases, indirect evidence of parathyroid hyperfunction such as intermittent hypercalcaemia (in 25 of the patients), hypercalciuria or a pathological response to calcium infusion. It is suggested that the patients with adenomas suffered from primary hyperparathyroidism (HPT), which however did not cause persisting hypercalcaemia. It seems likely that parathyroid hyperplasia either was a mild or an early form of primary HPT or secondary to increased calcium losses. In this study, no single laboratory feature could clearly separate the different groups. None of the patients with adenomas formed any new stone during follow-up (2-7 years) and also 40% of those with hyperplasia appeared to experience benefit from surgery. This benefit was more common in those with occasionally raised serum calcium values. In cases with borderline hypercalcaemia HPT is common and is cured by parathyroidectomy. However, in clinical practice the differential diagnosis may be difficult. In cases without firm evidence of HPT a conservative approach is favoured. Thiazides appear to reduce the stone recurrence rate in most euparathyroid patients and will probably help to unmask borderline HPT in recurrent renal stone formers.
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PMID:Clinical effects of parathyroid surgery in normocalcaemic patients with recurrent renal stones. 746 37

Development of sporadic parathyroid tumors is accompanied by loss of heterozygosity (LOH) on several chromosomes like 1p, 1q, 6q, 11q, and 15q. Here, we investigate a unique variant of familial hypercalcemia, unrelated to multiple endocrine neoplasia and hyperparathyroidism-jaw tumor syndromes, with hypercalcemia due to a point mutation in the intracellular part of the calcium receptor (CaR) gene. The hypercalcemia and hypercalciuria of the family is accompanied by age-related growth of the parathyroid glands and transition from diffuse to nodular parathyroid hyperplasia. Genome-wide screening for allelic loss was performed on nine enlarged parathyroid glands (weighing 40-680 mg) from eight parathyroidectomized members of the family (aged 22-66 yr). Using 139 fluorescent- or (32)P-labeled microsatellite markers, informative results were obtained on all examined chromosome arms and 1p, 1q, 6q, 11q, and 15q were investigated more closely. All parathyroid glands displayed allelic loss on at least one chromosomal arm (range 1-7). Most of the common loci for allelic loss corresponded to findings in sporadic parathyroid tumors, but the unique variant of familial hypercalcemia also exhibited frequent LOH on 12q (67%) and 7q (44%). LOH could not be detected at 3q, where the CaR gene is located, and additional somatic mutations in exons 2-7 of the CaR gene was not found by sequencing. The point mutation resulting in alteration of the intracellular portion of CaR seems to cause sensitivity to secondary genetic hits, with increased frequency of allelic loss (P < 0.01, r(2) = 0.66) and weight of parathyroid tumors with age in this family.
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PMID:Loss of heterozygosity in parathyroid glands of familial hypercalcemia with hypercalciuria and point mutation in calcium receptor. 1216 40

Activated vitamin D continues to be the major treatment for suppressing parathyroid hormone (PTH) levels in dialysis patients who have secondary hyperparathyroidism. Active vitamin D compounds are distinguished by their ability to bind with high affinity to vitamin D receptors (VDRs) not only in the parathyroid glands, but in cells throughout the body. Because of recent data showing that pulsatile, intravenous vitamin D treatment (calcitriol or paricalcitol) confers a survival advantage in the dialysis population, there is new interest in understanding the systemic effects of VDR activation, particularly in the predialysis stages of chronic kidney disease (CKD), where high mortality rates from cardiovascular disease have recently been documented. Previous underutilization of calcitriol treatment to control PTH levels in stages 3 and 4 CKD was often due to concerns about its potential for accelerating the progression of CKD as a consequence of hypercalcemia, hypercalciuria, or hyperphosphatemia. Vitamin D analogs with selective VDR activity (such as paricalcitol) have great potential for preventing parathyroid hyperplasia and bone loss in early CKD without adversely affecting kidney function. Whether they also reduce cardiovascular morbidity and mortality in early CKD, as they appear to do in dialysis patients, remains to be determined.
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PMID:Vitamin D treatment in chronic kidney disease. 1607 55