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)

Activating mutations of the Ca(2+)-sensing receptor (CaR) gene cause autosomal dominant hypoparathyroidism. Functional expression studies have been reported for several mutations, but have produced conflicting results. Thus, the mechanism by which these mutations activate the receptor is unclear. We describe here a new family with autosomal dominant hypoparathyroidism. The mother and three daughters experienced muscle spasms and/or seizures from early childhood. They were treated with oral calcium and vitamin D analogs, and all four patients developed hypercalciuria, nephrocalcinosis, and renal insufficiency. In this family, we identified a heterozygous missense mutation (F612S) involving the extracellular region of the CaR. The mutation cosegregated with disease. It was not present in 50 normal control individuals. We used site-directed mutagenesis to introduce this mutation into the CaR cDNA, and then expressed the mutant receptor in human embryonic kidney (HEK)-293 cells. In these cells, the accumulation of inositol phosphates was measured as a function of extracellular Ca2+ concentration. Compared with the wild-type receptor, the mutant receptor showed a left-shift in the concentration-response curve and an increase in the maximal response to high Ca2+ concentration. These effects did not appear to be mediated by changes in levels of receptor expression, as judged by ELISA, or by changes in receptor glycosylation, as judged by Western analysis. We conclude that this CaR mutation causes hypoparathyroidism by a dual increase in receptor sensitivity to extracellular Ca2+ and maximal signal transduction capacity.
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PMID:A Ca(2+)-sensing receptor mutation causes hypoparathyroidism by increasing receptor sensitivity to Ca2+ and maximal signal transduction. 938 Apr 34

A six-month-old, intact female Himalayan kitten was presented to the University of Tennessee Veterinary Medical Teaching Hospital for evaluation of chronic lethargy, inappetance, muscle tremors, and seizures. Upon physical examination, the kitten was very small for her age. Bilateral, incipient-to-immature cataracts were seen on ophthalmic examination. Severe hypocalcemia and concurrent hyperphosphatemia were identified on initial diagnostic evaluation. A diagnosis of primary hypoparathyroidism was made by identifying reduced concentrations of parathyroid hormone (PTH). The kitten responded well to treatment with calcium, vitamin D, and aluminum hydroxide and is clinically normal 17 months after initiation of treatment.
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PMID:Hypocalcemia and hyperphosphatemia due to primary hypoparathyroidism in a six-month-old kitten. 982 87

In patients with chronic renal failure, hyperparathyroidism is a common problem and surgical parathyroidectomy (PTX) is frequently required. The three different surgical approaches are subtotal PTX, total PTX with autotransplantation, and total PTX without autotransplantation. Recurrence of hyperparathyroidism varies from 5% to 80% in different studies for the first two surgical approaches. To minimize the risk for recurrence, and because we fear severe relapses with calciphylaxia, we perform total PTX without autotransplantation. From October 1993 to October 1997, 20 patients (9 men and 11 women) underwent total PTX without autotransplantation (median age, 52 years; range, 23 to 74 years; median dialysis time before PTX, 6.5 years; range, 1 to 22 years). All patients were supplemented with vitamin D analogues postoperatively. Patients were followed up for 1 to 48 months (median, 20 months). Bone pain, when present, disappeared within the first week after total PTX. Postoperatively, most patients had temporary hypocalcemia. In the long term, five patients had asymptomatic hypocalcemia. One patient, however, repeatedly had hypocalcemic seizures. Five patients developed asymptomatic hypercalcemia when supplemented with calcitriol. At the end of the individual's observation time, parathyroid hormone (PTH) levels were less than normal in six patients, normal in seven patients, and increased in seven patients despite total PTX. We conclude that total PTX should be reconsidered an option for the treatment of hyperparathyroidism secondary to renal failure. There was no evidence of clinical bone disease after total PTX. Apparently, remaining ectopic parathyroid tissue accounts for PTH levels after total PTX.
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PMID:Clinical course after total parathyroidectomy without autotransplantation in patients with end-stage renal failure. 1002 43

Based on recent international consensus conferences and a literature search, a brief summary is given of current knowledge about epilepsy in pregnancy. We suggest new Norwegian guidelines based on international recommendations for handling pregnant women with epilepsy. There is a slightly increased risk for malformations in children born of women with epilepsy. The main reason is probably teratogenic effects of antiepileptic drugs. Nevertheless, the overall chance of giving birth to a healthy child is 92-96%, compared to about 98% in the general population. Counselling all fertile women with epilepsy is important in order to reduce the risk of malformations. Before a planned pregnancy, medication should be re-evaluated, and the lowest dose of the drug most likely to give satisfactory seizure control is preferable. The women should have regular neurological follow-up throughout the pregnancy, and they should be given extra vitamin D, K, and folate. Women using carbamazepine, valproate or the new generation of antiepileptic drugs should be offered amniocentesis and comprehensive ultrasound examination in the 14th and 17th week, respectively. The newly approved drugs should be prescribed only if they provide a considerable better seizure control and/or fewer side effects than the traditional antiepileptic drugs.
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PMID:[Epilepsy and pregnancy]. 1055 42

Pseudohypoparathyroidism (PHP) is characterized by hypocalcemia and hyperphosphatemia due to PTH resistance. PHP type Ia is due to diminished G(s)alpha activity in several tissues, causing resistance to hormones whose action is mediated by cAMP. Only two cases of males with PTH type Ia who paradoxically showed sexual precocity have been described in the literature. We describe an 11.5 year-old boy affected by PHP without AHO but with associated true precocious puberty, who came to the I.C.U. for tetanic seizures and drowsiness due to severe hypocalcemia. Hyperphosphatemia, increased PTH levels and normal 25-OH-vitamin D values were present. Skeletal X-ray showed mild osteopenia. Brain MRI revealed symmetric calcifications in basal ganglia and in frontal areas. Thyroid and thyreotropinic function were normal. Testosterone levels were in the adult range, as well as basal and stimulated gonadotropin levels. Tanner stage P4, G4; testicular volume 12-15 mi. Molecular cytogenetics studies are now underway to further elucidate the etiology of this form of PHP.
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PMID:Gonadotropin-dependent sexual precocity in a boy affected by pseudohypoparathyroidism. 1096 32

The case of a neonate is presented who had late 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 'transient neonatal pseudohypoparathyroidism' was entertained, as the infant remained stable and seizure-free with normal serum biochemistry during 8 months of follow-up.
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PMID:Transient pseudohypoparathyroidism and neonatal seizure. 1133 28

Neurological manifestations of gastrointestinal disorders are described, with particular reference to those resembling multiple sclerosis (MS) on clinical or MRI grounds. Patients with celiac disease can present cerebellar ataxia, progressive myoclonic ataxia, myelopathy, or cerebral, brainstem and peripheral nerve involvement. Antigliadin antibodies can be found in subjects with neurological dysfunction of unknown cause, particularly in sporadic cerebellar ataxia ("gluten ataxia"). Patients with Whipple's disease can develop mental and psychiatric changes, supranuclear gaze palsy, upper motoneuron signs, hypothalamic dysfunction, cranial nerve abnormalities, seizures, ataxia, myorhythmia and sensory deficits. Neurological manifestations can complicate inflammatory bowel disease (e.g. ulcerative colitis and Crohn's disease) due to vascular or vasculitic mechanisms. Cases with both Crohn's disease and MS or cerebral vasculitis are described. Epilepsy, chronic inflammatory polyneuropathy, muscle involvement and myasthenia gravis are also reported. The central nervous system can be affected in patients with hepatitis C virus (HCV) infection because of vasculitis associated with HCV-related cryoglobulinemia. Mitochondrial neurogastrointestinal encephalopathy (MNGIE) is a disease caused by multiple deletions of mitochondrial DNA. It is characterized by peripheral neuropathy, ophthalmoplegia, deafness, leukoencephalopathy, and gastrointestinal symptoms due to visceral neuropathy. Neurological manifestations can be the consequence of vitamin B1, nicotinamide, vitamin B12, vitamin D, or vitamin E deficiency and from nutritional deficiency states following gastric surgery.
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PMID:Neurological manifestations of gastrointestinal disorders, with particular reference to the differential diagnosis of multiple sclerosis. 1179 74

Gain-of-function mutations of the calcium-sensing receptor (CaR) gene cause autosomal dominant and/or sporadic hypocalcemia with hypercalciuria. Because treatment of the hypocalcemia with vitamin D and/or calcium in patients with such mutations results in increased hypercalciuria, nephrocalcinosis, and renal impairment, its use should be limited to alleviating the symptoms of symptomatic patients. Because thiazide diuretics have been successfully used to treat patients with hypercalciuria and hypoparathyroidism, they are theoretically useful in reducing urine calcium excretion and maintaining serum calcium levels in patients with gain-of-function mutations of the CaR gene. In this study, we report on the clinical course, molecular analysis, and effects of hydrochlorothiazide therapy in two Japanese patients with gain-of-function mutations of the CaR gene. Within a few weeks after birth, they developed generalized tonic seizures due to hypocalcemia (serum calcium values: 1.1 mmol/liter and 1.3 mmol/liter, respectively). Despite treatment with the standard dose of 1,25-dihydroxyvitamin D(3) in one patient and 1alpha-hydroxyvitamin D(3) in the other, acceptable serum calcium levels near the lower limit of normal were not established, and their urinary calcium excretion inappropriately increased. Addition of hydrochlorothiazide (1 mg/kg) reduced their urinary calcium excretion and maintained their serum calcium concentrations near the lower limit of normal, allowing the 1,25-dihydroxyvitamin D(3) and 1alpha-hydroxyvitamin D(3) doses to be reduced, and it alleviated their symptoms. A heterozygous missense mutation was identified in both patients. In one patient, the mutation was A843E in the seventh transmembrane domain of the CaR, and in the other it was L125P in the N-terminal extracellular domain. In vitro transient transfection of their mutant CaR cDNAs into HEK293 cells shifted the concentration-response curve of Ca(2+) to the left. In conclusion, two sporadic cases of hypercalciuric hypocalcemia were due to de novo gain-of-function mutations of the CaR gene. Hydrochlorothiazide with vitamin D(3) successfully reduced the patients' urinary calcium excretion and controlled their serum calcium concentrations and symptoms. Thiazide diuretics are effective in patients with gain-of function mutations of the CaR gene.
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PMID:Hydrochlorothiazide effectively reduces urinary calcium excretion in two Japanese patients with gain-of-function mutations of the calcium-sensing receptor gene. 1210 2

Rickets usually occurs in the first two years of life and in puberty since metabolic demand is increased due to rapid growth in these two critical periods of life, when peak bone mass is achieved. Rickets remains one of the most prevalent pediatric diseases in developing countries. Although it is considered to have disappeared in developed countries, there is increasing evidence of widespread vitamin D deficiency among immigrants. There are many reports on rickets and osteomalacia in Asian infants, adolescents and pregnant women moving from India, Pakistan and Bangladesh to developed countries with a cooler climate. We describe three teenagers of Pakistani origin. Clinical presentation included limb pains, muscular weakness, knock-knees and seizures. In all three patients, biochemical findings included hypocalcemia, raised serum parathormone and alkaline phosphatase, and reduced 25-hydroxy vitamin D concentrations. After vitamin D treatment and dietary counseling, biochemical findings returned to normal and their symptoms improved. Given the recent increase in the number of immigrants to Spain, this forgotten disease will probably reappear.
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PMID:[Rickets in Asian immigrants during puberty]. 1219 51

Nutritional rickets is a serious disease that is infrequently encountered in the United States today because of the fortification of infant formulas and dairy products with vitamin D. We report a case of undiagnosed nutritional rickets presenting with recurrent febrile seizures. Febrile seizures, a common and usually benign presenting complaint, are not among the symptoms generally known to be associated with rickets. Therefore, the disease was uncovered only after a careful history and physical examination prompted a more thorough investigation into an underlying cause for recurrent seizures. The diagnosis was subsequently confirmed by quantitative laboratory testing. We review the historical and cultural factors, symptoms, and physical findings suggestive of this potentially serious yet easily treatable disease.
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PMID:First place winner. Recurrent febrile seizures: an unusual presentation of nutritional rickets. 1248 16


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