Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0036572 (seizures)
 80,221 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A novel missense activating mutation in the extracellular calcium-sensing receptor (CaSR) is reported in this work. It was identified in three related subjects with the phenotypic features of autosomal dominant hypocalcemia (ADH). The proband, a 27-year-old woman, diagnosed as having hypoparathyroidism at 7 years of age and a history of seizures, showed the highest penetrance of the mutation. The remaining two affected members presented asymptomatic chronic hypocalcemia despite severe hypoparathyroidism associated with high levels of serum phosphate and calcium urinary excretion. The missense mutation (Glu(604)Lys) affected an amino acid residue in the C terminus of the cysteine-rich domain of the extracellular amino-terminal domain, which seems to be required for the coupling of ligand binding to the activation of intracellular signaling pathways. This genetic change cosegregated with hypocalcemia in all the individuals where the mutation was found. As parathyroid hormone (PTH) secretion is the regulatory target of the CaSR, polymorphism analysis of the PTH gene was carried out. PTH polymorphisms were analyzed in the kindred studied. Affected members for the Glu(604)Lys CaSR mutation which also carried the uncommon PTH alleles showed higher penetrance of the mutation, with more severe autosomal dominant hypocalcemia. These results suggested that the PTH gene could act as a modifier locus of ADH, affecting the penetrance of the activating CaSR mutation described.
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PMID:A novel mutation in the calcium-sensing receptor responsible for autosomal dominant hypocalcemia in a family with two uncommon parathyroid hormone polymorphisms. 1451 94

Hypoparathyroidism, a life threatening disorder, occurs when insufficient parathyroid hormone is produced to maintain extracellular calcium levels within the normal range. The acute clinical signs and symptoms of hypoparathyroidism are the same as those of hypocalcemia, ranging from tingling to intractable generalized tonic-clonic seizures; therefore, it can be mistaken for epilepsy. We report the case of a 36-year-old man who presented two tonic-clonic seizures, characterized by sudden loss of consciousness with a fall and diffuse tonic contractions and clonic jerks. At first diagnosis of epilepsy was established and therapy with valproate was commenced. In the following days, the patient presented typical signs of hypocalcemia and the diagnosis of hypoparathyroidism was made. In the 4 months follow up, antiepileptic drug therapy was reduced until suspension and calcium supplementation was initiated. We briefly review the most recent reports in the literature.
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PMID:Tonic-clonic seizures in a patient with primary hypoparathyroidism: a case report. 1516 18

This study aimed to investigate the relationship between 25-hydroxyvitamin D [25(OH)D)] and parathyroid hormone (PTH) levels in adolescent females residing in a northern climate. Concern regarding vitamin D status in this population is due to limited sunlight exposure in northern latitudes, decreased outdoor recreational activities, as well as decreased conversion in black girls from increased skin pigmentation. In this cross-sectional analysis, serum samples were assayed for 25(OH)D using competitive protein binding (CPB) assay and PTH with immuno-radiometric (RIA) procedures. Four hundred postmenarcheal females (12-18 years) residing in northeastern Ohio were recruited. Subjects were excluded if they had a history of bone, kidney, or liver disease, or used medications that affect bone. The primary goal was to determine serum 25(OH)D concentrations in relation to circulating PTH levels in a population of adolescent girls. The Spearman correlation test was used to compare PTH and 25(OH)D. Fit multiple split models were run to determine change in slope of the regression line when 25(OH)D and PTH were plotted. Analysis of variance was determined using modeled means with differences by race and season in the final model. Unadjusted mean serum 25(OH)D and PTH levels were 55.0+/-30.4 nmol/l and 39.4+/-20.6 ng/l, respectively. Blacks had lower 25(OH)D and higher PTH compared with non-blacks (P<0.0001), especially during the winter months. Decreasing 25(OH)D was inversely correlated with PTH (r=-0.314) (P<0.0001), and at concentrations of 25(OH)D < or =90 nmol/l, an increase in PTH was observed. Adolescents are at risk for decreased serum 25(OH)D concentrations, especially black girls. We found that the widely used cutoff for vitamin D deficiency is associated with increasing PTH levels and is below the inflection point for a change in the slope of the regression line. Our results support the need for further research to establish optimal vitamin D status in adolescent girls.
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PMID:Low levels of 25-hydroxy vitamin D are associated with elevated parathyroid hormone in healthy adolescent females. 1517 48

Mutations in the calcium-sensing receptor gene (CaSR) may result in disorders of calcium homeostasis manifesting as familial benign hypocalciuric hypercalcaemia (FBHH), neonatal severe hyperparathyroidism (NSHPT) or autosomal dominant hypocalcaemia with hypercalciuria (ADHH). FBHH may have a population prevalence as high as one in 16 000, and ADHH one in 70 000. NSHPT is very rare. The FBHH condition is usually asymptomatic. Parathyroidectomy does not result in normal serum calcium, and no active treatment is indicated. To differentiate FBHH from primary hyperparathyroidism (PHPT), a guideline which includes measurement of serum calcium, intact parathyroid hormone (PTH), magnesium and fasting urinary calcium excretion is proposed. Screening of family members for hypercalcaemia, and occasionally a search for mutations in the CaSR gene, may be required. The NSHPT condition may manifest with hypercalcaemia, (usually) very elevated serum PTH concentration, subperiosteal erosions and fractures. Milder cases may be managed medically, but respiratory failure, extreme hypercalcaemia and failure to thrive are indications for early parathyroidectomy. The ADHH condition may result in asymptomatic hypocalcaemia, but some affected family members have minor symptoms, and a minority experience seizures in infancy which can recur into adulthood. A significant proportion of cases previously reported as idiopathic hypoparathyroidism (IHP) may in fact be due to mutations in the CaSR gene. In a moderately hypocalcaemic patient with no other clearly discernible cause, an elevated urine calcium:creatinine ratio is suggestive of ADHH, as is the presence of a first-degree relative with hypocalcaemia. If treatment with vitamin D analogues is undertaken, serum and urine calcium should be monitored, advice which applies equally to ADHH and IHP.
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PMID:Clinical and laboratory features of calcium-sensing receptor disorders: a systematic review. 1558 33

Primary hypoparathyroidism was diagnosed in three St. Bernard bitches. Anorexia, behavioural changes, muscle tremors, seizures, panting respiration, and cataracts were the clinical signs observed. The serum concentration of calcium was low, the phosphorus concentration elevated, and the immunoreactive parathyroid hormone level low in all dogs. The aetiology of the hypoparathyroidism was not determined in any of the dogs. Treatment with synthetic vitamin D (1,25-dihydroxycholecalciferol) and an oral calcium supplement was successful in restoring and then maintaining a normal concentration of serum calcium in two of the dogs.
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PMID:Primary idiopathic hypoparathyroidism in St. Bernard dogs. 1603 Nov 73

Autosomal dominant hypocalcaemia with hypercalciuria (ADHH) is an intriguing syndrome, in which activating mutations of the calcium sensing receptor (CaSR) have recently been recognised. We describe a kindred with seven affected individuals across three generations, including patients affected in the first decade of life. Age at diagnosis varied from birth to 50 years. Affected members had hypocalcaemia (1.53-1.85 mmol/l), hypercalciuria, low but detectable parathyroid hormone (PTH) and hypomagnesaemia. Four of seven affected individuals were symptomatic (seizures, abdominal pains and paraesthesias), unrelated to severity of hypocalcaemia. Additional complications include nephrocalcinosis (n = 3) and basal ganglia calcification, identified by CT scanning in all five individuals. Symptomatic individuals were treated with calcium and calcitriol to reduce the risk of hypocalcaemic seizures. DNA sequence analysis, identified a mutation in exon 3, codon 129 (TGC-->TAC) of the CaSR gene of seven affected family members, resulting in loss of a conserved cysteine residue, potentially disrupting CaSR receptor dimerisation. Thus, a novel mutation was identified in this family, who demonstrate variability of ADHH phenotype and also illustrate the complexities of clinical management. Optimal management of ADHH is difficult and we recommend judicious treatment to avoid an increased risk of nephrocalcinosis.
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PMID:A family with autosomal dominant hypocalcaemia with hypercalciuria (ADHH): mutational analysis, phenotypic variability and treatment challenges. 1612 46

Klinefelter's syndrome is rarely associated with hypocalcemia, especially pseudohypoparathyroidism (PHP) type Ib. We describe a case of Klinefelter's syndrome associated with seizure, PHP type Ib and multiple endocrine dysfunctions. A 19-year-old Taiwanese male was admitted due to seizures with loss of consciousness. He had been diagnosed with Klinefelter's syndrome with seizure disorder and hypocalcemia 3 months previously. Physical examination revealed eunuchoidism but no osteodystrophy, while laboratory data revealed severe hypocalcemia, hyperphosphatemia, and elevated parathyroid hormone. Chromosomal study showed 47,XXY. Osteoporosis was found on chest and abdominal radiography. Dense calcification in the cerebrum and cerebellum was shown on brain computed tomography and magnetic resonance imaging. Elevation of the patient's serum calcium level was noted after vitamin D and calcium carbonate supplements were given. Klinefelter's syndrome is rarely associated with PHP type Ib; our patient's hypocalcemia improved after long-term aggressive treatment.
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PMID:Klinefelter's syndrome with seizure, pseudohypoparathyroidism type Ib and multiple endocrine dysfunctions. 1637 43

The case of a neonate is presented who had early onset seizure associated with hypocalcemia, hyperphosphatemia, and raised parathyroid hormone. The infant did not have any stigmata of pseudohypoparathyroidism. The hypocalcemia was initially resistant to calcium therapy, but responded to vitamin D analog therapy. The diagnosis of 'neonatal pseudohypoparathyroidism' was entertained; the infant remained stable and seizure-free with normal serum biochemistry during 3 months of follow-up.
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PMID:Neonatal pseudohypoparathyroidism. 1644 71

We report here on a girl and her father with HDR syndrome (Hypoparathyroidism, sensorineural Deafness and Renal anomaly syndrome). The proband, an 11 year-old girl, complained of periodic tetany lasting for 6 years, and also used a hearing aid because of sensorineural hearing impairment. Furthermore, she had hemimegalencephaly, and had been taking an anti-epileptic agent to treat psychomotor seizures for 6 years. Endocrine assessment showed modest hypocalcemia, hyperphosphatemia and hypophosphaturia with lower normal parathyroid hormone concentration, and she had no renal abnormalities. Her father, who was 40 years old at the time of the investigation, had sensorineural hearing impairment, a lower than normal calcium level and normal renal function. Direct sequencing after PCR amplification of genomic DNA revealed a novel insertional mutation (405insC) in the GATA3 gene of both patients. This mutation was hypothesized to disrupt dual zinc fingers as well as one transactivating domain. The present findings lend additional support to the notion that the phenotype cannot be precisely estimated from the genotype in HDR syndrome.
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PMID:A novel mutation in the GATA3 gene in a family with HDR syndrome (Hypoparathyroidism, sensorineural Deafness and Renal anomaly syndrome). 1650 33

Pseudohypoparathyroidism (PHP) is a rare inherited syndrome with several types. We reviewed the cases of 7 PHP patients seen between 1990 and 2003, and analyzed their clinical, biochemical data and long-term medical outcomes. Six boys and one girl were included. Two siblings showed Albright's hereditary osteodystrophy (AHO) and PHP Ia was impressed. The rest were suspected of PHP Ib. Their mean diagnosed age was 10.8 years and most had symptoms onset for several years before diagnosis. The most frequent initial presentations were seizure, followed by extremity muscle spasm, short stature, learning disability and psychomotor retardation. Mild thyrotropin elevation was noted in two patients of PHPIa. Early puberty onset, combined with bone age advancement was noted in the boy with PHP Ia, who had the shortest predicted adult height (PAH) (139.5 cm). The other 5 boys had normal PAH, mean 171.42 cm, and 4 male patients reached final height with a mean of 163.25 cm, close to their target heights. During treatment, 2 patients developed nephrocalcinosis. In conclusion, subtypes of PHP present heterogeneous phenotypes. Non-Ia subtypes might not be rare in Taiwan. Therefore, in hypocalcemic patients with mild high or normal parathyroid hormone (PTH), even in the absence of AHO, PHP should be ruled out. Regular renal sonography follow-up is recommended during therapy.
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PMID:Pseudohypoparathyroidism: report of seven cases. 1664 41


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