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)

We describe 11 infants with congenital lactase deficiency, whose age at diagnosis varied from 6 to 88 days. At the time of admission, 7 of 10 infants had hypercalcemia. Five of the seven infants for whom renal ultrasonography was performed at the time of diagnosis had medullary nephrocalcinosis. Hypercalcemia ceased within a week of the start of a lactose-free diet. At the time of reevaluation, at the ages of 2 to 10 years, one of the patients still had hypercalciuria and nephrocalcinosis was still present in 3 of 11 patients. The mechanism of hypercalcemia is unclear but may be related to metabolic acidosis or may be promoted by the lactose effect (i.e., by nonhydrolyzed lactose that has a direct enhancing effect on calcium absorption in the ileum).
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PMID:Hypercalcemia and nephrocalcinosis in patients with congenital lactase deficiency. 852 89

Eight patients (6 women and 2 men) with osteoporosis caused or aggravated by renal acidification defects are presented. Three of the female patients were premenopausal; the others were 9, 20 and 22 years postmenopausal, and two of them were on hormonal replacement therapy. Two patients had nephrolithiasis: one male with recurrent calcium phosphate stones and a left sided staghorn calculus, and one female with nephrocalcinosis due to medullary sponge kidney and hypercalciuria (patients No. 1 and 2, respectively, Table 1). In the remaining subjects, clinical suspicion was based on: a) Hip fracture in a 44-yr-old premenopausal female without any risk factor (No. 3, Table 2). b) Several vertebral compression fractures in a 45-yr-old male without hypogonadism or other predisposing factors (No. 7, Table 2). c) Lack of response to antiosteoporotic therapy in 3 women (patients No. 4, 6 and 8, Table 2). Serum bicarbonate levels and urine acidification capacity were studied in all patients. Three had low serum bicarbonate (two of whom showed high fractional excretion of bicarbonate), four had a distal defect, and one had a mixed form. Serum creatinine and potassium, and venous blood pH were normal in all cases, suggesting incomplete renal tubular acidosis. Bone mineral density in Z-score (means +/- s.e.m.) was - 1.75 +/- 0.08 in the lumbar spine (n = 8), and - 1.57 +/- 0.09 in the femoral neck (n = 4) [Tables 1 and 2; Figs 1 and 2]. Following one year treatment with oral sodium bicarbonate and potassium citrate, total skeletal calcium increased by 3-10% in five of the patients. Whereas the high prevalence of renal acidification defects among renal stone formers with or without hypercalciuria is well acknowledged, renal tubular acidosis is not included in the list of entities causing secondary osteoporosis. As shown in 6 patients of this series, incomplete RTA should be considered as another disease capable of causing osteoporosis or worsening involutional bone loss.
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PMID:[Renal acidification mechanism disorders in patients with osteoporosis]. 854 15

Dent disease, an X-linked familial renal tubular disorder, is a form of Fanconi syndrome associated with proteinuria, hypercalciuria, nephrocalcinosis, kidney stones, and eventual renal failure. We have previously used positional cloning to identify the 3' part of a novel kidney-specific gene (initially termed hClC-K2, but now referred to as CLCN5), which is deleted in patients from one pedigree segregating Dent disease. Mutations that disrupt this gene have been identified in other patients with this disorder. Here we describe the isolation and characterization of the complete open reading frame of the human CLCN5 gene, which is predicted to encode a protein of 746 amino acids, with significant homology to all known members of the ClC family of voltage-gated chloride channels. CLCN5 belongs to a distinct branch of this family, which also includes the recently identified genes CLCN3 and CLCN4. We have shown that the coding region of CLCN5 is organized into 12 exons, spanning 25-30 kb of genomic DNA, and have determined the sequence of each exon-intron boundary. The elucidation of the coding sequence and exon-intron organization of CLCN5 will both expedite the evaluation of structure/function relationships of these ion channels and facilitate the screening of other patients with renal tubular dysfunction for mutations at this locus.
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PMID:Cloning and characterization of CLCN5, the human kidney chloride channel gene implicated in Dent disease (an X-linked hereditary nephrolithiasis). 857 51

The causes of the development of nephrocalcinosis in familial hypophosphatemic rickets (FHR) are reviewed. The treatment combines vitamin D or 1,25 dihydroxyvitamin D and oral phosphate supplementation. Hypercalcaemia and hypercalciuria were thought to cause the renal calcification. On the basis of the data of eighteen patients with familiar hypophosphatemic rickets we have found that the main difference between the treatment of patients having nephrocalcinosis and those with normal renal morphology consisted in the dose of oral phosphate intake. Patients with nephrocalcinosis received significantly higher doses of oral phosphate (130 mg/kg/day versus 70 mg/kg/day, p < 0.01). Correspondingly, their urinary phosphate excretion was also significantly higher (p < 0.01). There was no difference between the two groups with respect of the doses of vitamin D and urinary calcium excretion. It can be concluded, that high concentrations of urinary phosphate can lead to nephrocalcinosis even if urinary calcium concentration is normal. In order to prevent nephrocalcinosis in patients with X-linked hypophosphatemia, the following guide-lines could be recommended: 1) urinary calcium excretion should be kept lower, than the usually allowed < 4 mg/kg/day; 2) oral phosphate supplementation should not exceed 100 mg/kg/day, 3) patients should be encouraged to drink large amounts of water, 4) regular ultrasound controls should be part of the routine follow-up.
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PMID:Guide-lines to the treatment of patients with X-linked hypophosphatemic rickets. 857 31

The introduction of renal ultrasound technology has shown renal calcification to be more common in infancy than was previously believed. Understanding the role of inhibitors and promoters in crystal formation helps elucidate the pathophysiology of nephrocalcinosis. Identification of the presence or absence of hypercalcemia and hypercalciuria is an effective way to direct the diagnostic work-up of infants with nephrocalcinosis. The sonographic image of renal calcification resolves spontaneously in many infants. Whether microscopic nephrocalcinosis persists below the threshold of ultrasonographic detection is unknown. Renal calcification can be associated with persistent renal function abnormalities if hypercalciuria continues, such as in VLBW infants who receive long-term furosemide therapy after discharge from the hospital. Renal calcification may also progress to renal failure, such as in infants with primary hyperoxaluria, owing to the persistence of hyperoxaluria, a potent promoter of calcium crystal formation.
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PMID:Renal calcification in the first year of life. 861 92

Hypercalcemia occurs in about 10% of the patients with sarcoidosis; hypercalciuria is about three times more frequent. These abnormalities of calcium metabolism are due to dysregulated production of 1,25-(OH)2-D3 (calcitriol) by activated macrophages trapped in pulmonary alveoli and granulomatous inflammation. Undetected hypercalcemia and hypercalciuria can cause nephrocalcinosis, renal stones, and renal failure. Corticosteroids cause prompt reversal of the metabolic defect. Chloroquine, hydroxychloroqune, and ketoconazole are the drugs that should be used if the patient fails to respond or develops dangerous side effects to corticosteroid therapy.
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PMID:Vitamin D, calcium, and sarcoidosis. 862 Jul 32

1. The best way to prevent early growth failure in children with renal disease is by the use of specified nutrition and appropriate buffer, activated vitamin D, and calcium-containing phosphate binders as needed. With prenatal diagnosis of anatomically abnormal kidneys available, this type of early intervention may be much more feasible in the 1990s. 2. Supplemental sodium and water in children with polyuria and intravascular volume depletion may prevent growth failure. Cow milk is detrimental in this group of individuals because of high solute and protein load, often causing intravascular volume depletion, hyperphosphatemia, and acidosis. 3. Children with acquired glomerular disease may need sodium restriction and, if treated with steroids, a diet low in saturated fat. 4. Children with nephrotic syndrome and severe edema should be evaluated for malabsorption and subsequent malnutrition. Protein intake should be supplemented only at the RDA and to replace ongoing losses. Long-term sodium restriction is appropriate. Hyperlipidemia should be monitored: if nephrosis is chronic, a low saturated fat diet should be instituted. Angiotensin-converting enzyme inhibitors can decrease urinary protein loss and may ameliorate hyperlipidemia. Children resistant to therapy can have very high morbidity. 5. Children with <50 % of normal creatinine clearance should have PTH measured and activated vitamin D therapy should be started if PTH is elevated more than two to three times normal. Thereafter careful monitoring of calcium, phosphorus, and PTH is crucial to prevent renal osteodystrophy, low turnover bone disease, and hypercalcemia with hypercalciuria and nephrocalcinosis. 6. Children with tubular defects with severe polyuria also may benefit from low-solute, high-volume feedings. 7. All physicians caring for children with renal disease should have pediatric nephrology consultation available. Prevention of growth failure is much more cost effective than pharmacologic therapy. Before initiating growth hormone treatment for growth retardation, assiduous treatment of co-existing renal osteodystrophy and provision of optimal nutritional intake should be accomplished.
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PMID:Nutritional management of the child with mild to moderate chronic renal failure. 876 44

An additional case of Bartter syndrome is reported, along with its metabolic and clinical features. Emphasis is laid on the concept that an early diagnosis may improve the clinical outcome of the disease, thanks to the prompt use of indomethacin therapy which is capable of preventing hypercalciuria and nephrocalcinosis.
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PMID:[Bartter's syndrome: a case report of nephrocalcinosis]. 876 66

A girl presented at the age of 8 months with idiopathic infantile hypercalcaemia complicated by hypercalciuria, nephrocalcinosis and failure to thrive. Her hypercalcaemia was partially corrected by prednisolone, but resolved with the addition of cellulose phosphate. Her height and weight showed significant improvement during the treatment period. Cellulose phosphate should be considered in the management of children with idiopathic infantile hypercalcaemia and nephrocalcinosis.
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PMID:Prednisolone and cellulose phosphate treatment in idiopathic infantile hypercalcaemia with nephrocalcinosis. 884 45

The aim of the study was to characterize abnormalities of calcium-phosphate and vitamin D3 metabolism in children with a past history of "mild" Lightwood-type idiopathic infantile hypercalcaemia. Seventeen seemingly healthy children aged 2-12 years, with long-term idiopathic hypercalcaemic syndrome since infancy were studied. Two reference groups were also included (vitamin D3 intoxication/healthy and Williams groups). Despite a long-term milk-restricted diet and a restricted vitamin D3 intake, urinary calcium excretion in the study group was 0.117 +/- 0.07 mumol/kg per 24 h. Compared with the reference groups (0.047 +/- 0.029 and 0.067 +/- 0.06 mumol/kg per 24 h, P < 0.05), there was significant hypercalciuria in the children with idiopathic hypercalcaemia since infancy. Serum concentrations of 25-hydroxyvitamin D3 in the study group were also elevated compared with the reference groups (57.4 +/- 15.5 vs. 34.6 +/- 9.3 and 22.7 +/- 10.5 ng/ml). 1,25-Dihydroxyvitamin D3 levels were at the upper limit of normal (45.9 +/- 13.1 vs. 35.0 +/- 8.1 and 30.0 +/- 13.7 pg/ml). Non-progressive, clinically silent nephrocalcinosis was visible on ultrasound examinations. The disturbances of vitamin D3 and calcium-phosphate metabolism persistent in the normocalcaemic phase of idiopathic infantile hypercalcaemia may be a primary metabolic defect of the condition. The mechanisms leading to elevation of metabolites of 1,25-dihydroxy- and 25-hydroxyvitamin D3 and the relationship between this and persistent hypercalciuria and nephrocalcinosis need pathophysiological explanation.
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PMID:Persistent hypercalciuria and elevated 25-hydroxyvitamin D3 in children with infantile hypercalcaemia. 903 62


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