1/25. Transient pseudo-hypoaldosteronism following resection of the ileum: normal level of lymphocytic aldosterone receptors outside the acute phase.Pseudo-hypoaldosteronism (PHA) is due to mineralocorticoid resistance and manifests as hyponatremia and hyperkalemia with increased plasma aldosterone levels. It may be familial or secondary to abnormal renal sodium handling. We report the case of a 54-year-old woman with multifocal cancer of the colon, who developed PHA after subtotal colectomy, ileal resection and jejunostomy. She was treated with 6 g of salt daily to prevent dehydration, which she stopped herself because of reduced fecal losses. One month later she was admitted with signs of acute adrenal failure, i.e. fatigue, severe nausea, blood pressure of 80/60 mmHg, extracellular dehydration, hyponatremia (118 mmol/l); hyperkalemia (7.6 mmol/l), increased blood urea nitrogen (BUN) (200 mg/dl) and creatininemia (2.5 mg/dl), and decreased plasma bicarbonates level (HCO3-: 16 mmol/l; N: 27-30). However, the plasma cortisol was high (66 microg/100 ml at 10:00 h; N: 8-15) and the ACTH was normal (13 pg/ml, N: 10-60); there was a marked increase in plasma renin activity (>37 ng/ml/h; N supine <3), active renin (869 pg/ml; N supine: 1.120), aldosterone (>2000 pg/ml; N supine <150) and plasma AVP (20 pmol/l; N: 0.5-2.5). The plasma ANH level was 38 pmol/l (N supine: 5-25). A urinary steroidogram resulted in highly elevated tetrahydrocortisol (THF: 13.3 mg/24h; N: 1.4 /-0.8) with no increase in tetrahydrocortisone (THE: 3.16 mg/24h; N: 2.7 /-2.0) excretion, and with low THE/THF (0.24; N: 1.87 /-0.36) and alpha THF/THF (0.35; N: 0.92 /-0.42) ratios. The number of mineralocorticoid receptors in mononuclear leukocytes was in the lower normal range for age, while the number of glucocorticoid receptors was reduced. Small-bowel resection in ileostomized patients causes excessive fecal sodium losses and results in chronic sodium depletion with contraction of the plasma volume and severe secondary hyperaldosteronism. Nevertheless, this hyperaldosteronism may be associated with hyponatremia and hyperkalemia suggesting PHA related to the major importance of the colon for the absorption of sodium. In conclusion, this case report emphasizes 1) the possibility of a syndrome of acquired PHA with severe hyperkalemia after resection of the ileum and colon responding to oral salt supplementation; 2) the major increase in AVP and the small increase in ANH; 3) the strong increase in urinary THF with low THE/THF and alpha THF/THF ratios; 4) the normal number of lymphocytic mineralocorticoid receptors outside the acute episode.- - - - - - - - - - ranking = 1keywords = syndrome (Clic here for more details about this article) |
2/25. A patient with pseudohypoaldosteronism type 1 and respiratory distress syndrome.We present a patient born at 36 weeks' gestation with respiratory distress, who required 6 days of mechanical ventilation, without a demonstrable infectious cause. He also developed hyponatremia, hypernatriuria, elevated serum aldosterone levels, and probable pseudohypoaldosteronism type 1 (PHA-1). This appears to be the first reported human case of both respiratory distress and a renal salt wasting process with elevated serum aldosterone. In animal models, abnormalities of subunits of the epithelial sodium channel produce respiratory distress and PHA-1. This patient's clinical presentation could be due to the same processes.- - - - - - - - - - ranking = 4keywords = syndrome (Clic here for more details about this article) |
3/25. Gordon's syndrome: increased maximal rate of the Na-K-Cl cotransport and erythrocyte membrane replacement of sphingomyelin by phosphatidylethanolamine.OBJECTIVE: Gordon's syndrome comprises hypertension, hyperchloremic acidemia, hyperkalemia and intact renal function. We hypothesize that disturbances of one or more cell membrane ion carriers, handling sodium, chloride and potassium, might be relevant in this disorder and, furthermore, that such disturbances might be related to altered.cell membrane composition. DESIGN AND methods: In a patient diagnosed with Gordon's syndrome, we assessed the kinetics (K(m) and maximal rate) of four membrane sodium transport systems in sodium-enriched erythrocytes, according to the technique of Garay. We also measured the lipid composition of erythrocyte membrane in this patient and 69 essential hypertensive controls, using the latroscan technique. RESULTS: Compared to reference values of patients with essential hypertension, this patient exhibited a marked increase in the maximal rate of the Na -K -2Cl(-)-cotransport (964.0 micromol/l per cell versus the 391.6 /- 222 micromol/l per cell in essential hypertensives). Also, there was an increased concentration of erythrocyte membrane phosphatidylethanolamine and a reduced concentration of sphingomyelin (27.9 and 11.1% versus 17.9 /- 3.8% and 18.2 /- 3.4%, respectively). CONCLUSIONS: We conclude that this abnormality in membrane Na -K -2Cl- cotransport could be responsible for the hyperkalemia, hyperchloremic acidemia and increased reabsorption of sodium observed in this condition and, furthermore, that such disturbance in membrane cotransport might be related to altered phospholipid concentration in cell membranes.- - - - - - - - - - ranking = 6keywords = syndrome (Clic here for more details about this article) |
4/25. pseudohypoaldosteronism: mineralocorticoid unresponsiveness syndrome.We described a 10 day old boy who presented with hyponatremia, hyperkalemia, and metabolic acidosis. Therapeutic treatment with exogenous glucocorticoid and mineralocorticoid for 8 months failed to correct the electrolyte abnormalities. The elevated serum cortisol up to 44.34 micrograms/dl along with the absence of skin hyperpigmentation excluded defects in the glucocorticoid pathway. pseudohypoaldosteronism was diagnosed on the basis of hyponatremia, severe urinary salt loss despite the markedly elevated serum aldosterone up to 6,500 pg/ml (normal range 50-800 pg/ml). The patient responded very well to oral salt supplementation and cation exchange resin therapy shown by normal physical growth and normal levels of serum electrolytes.- - - - - - - - - - ranking = 4keywords = syndrome (Clic here for more details about this article) |
5/25. Systemic pseudohypoaldosteronism from deletion of the promoter region of the human Beta epithelial na( ) channel subunit.Systemic pseudohypoaldosteronism type I (PHAI) is an autosomal recessive disorder that arises from loss of function mutations of the alpha, beta, or gamma subunit of Epithelial Na( ) Channel (ENaC). In addition to a severe renal phenotype in the neonatal period, patients with PHAI develop a childhood pulmonary syndrome characterized by cough and frequent respiratory infections. We tested a patient, born to consanguineous parents, who presented with dehydration, metabolic acidosis, hyperkalemia, elevated renin and aldosterone levels at birth, and recurrent respiratory symptoms in his first year. He demonstrated defective epithelial Na( ) transport in multiple organs (raised sweat Cl(-), 120 mM; raised salivary Na( ) and Cl(-), 118 and 111 mM, respectively; and little nasal amiloride-sensitive potential difference). No deleterious mutation was identified in the coding region of the three ENaC subunits. Reverse transcriptase-polymerase chain reaction of nasal epithelial rna showed reduced betaENaC expression, and inability to amplify promoter elements indicated the possibility of a deletion in the 5' region. Using a probe that corresponded to exon 1A of betaENaC, we confirmed a large deletion (> 1,300 bp). In summary, a homozygous mutation in the promoter region of betaENaC leads to PHAI, the first description of a mutation in the regulatory regions of an ENaC subunit leading to a clinical phenotype.- - - - - - - - - - ranking = 1keywords = syndrome (Clic here for more details about this article) |
6/25. A novel mutation of the epithelial Na channel causes type 1 pseudohypoaldosteronism.Type I pseudohypoaldosteronism (PHA-1) is a rare salt wasting syndrome occurring soon after birth, characterized by apathy and severe dehydration accompanied by hyponatremia, hyperkalemia, and metabolic acidosis despite high plasma aldosterone concentrations. The molecular defect involved in the systemic autosomal recessive form of the syndrome has been identified. Mutations in all three genes encoding the epithelial sodium channel (ENaC) lead to a decrease in the channel function, resulting in the disease. We report here two new cases of the autosomal recessive form of PHA-1 in the same family. We found a new homozygous mutation of the gene encoding the alpha ENaC subunit (alphaR492stop). The function of the mutated ENaC channel was assessed in the xenopus laevis oocyte expression system. The mutant ENaC activity measured with the two-electrode voltage clamp method was drastically decreased compared with the wild type activity, in agreement with the salt-losing phenotype.- - - - - - - - - - ranking = 2keywords = syndrome (Clic here for more details about this article) |
7/25. pseudohypoaldosteronism type 1 and respiratory distress syndrome.We present a patient born at 31 weeks gestation with respiratory distress syndrome (RDS) which did not respond to surfactant. He also developed hyponatremia, hyperkalemia and dehydration with increased sweat electrolytes despite high levels of serum aldosterone, thus systemic pseudohypoaldosteronism type 1 (PHA-1) diagnosis was made. Systemic PHA-1 is caused by mutations of amiloride-sensitive epithelial sodium channel (ENaC) genes. Because ENaC is a rate-limiting step for sodium absorption by epithelial cells, not only of the renal tubule but also of the lung epithelium, patients with PHA-1 with pulmonary symptoms have sometimes been reported. However, our patient appears to be the second reported human case of both neonatal RDS and PHA-1, and the first description, with increased sweat electrolytes, of a premature baby with systemic PHA-1 and RDS.- - - - - - - - - - ranking = 5keywords = syndrome (Clic here for more details about this article) |
8/25. Heterozygous mutations of the gene for Kir 1.1 (ROMK) in antenatal bartter syndrome presenting with transient hyperkalemia, evolving to a benign course.Bartter-like syndrome encompasses a set of inherited renal tubular disorders associated with hypokalemic metabolic alkalosis, renal salt wasting, hyperreninemic hyperaldosteronism, and normal blood pressure. Antenatal bartter syndrome, a subtype of Bartter-like syndrome, is characterized by polyhydramnios, premature delivery, life-threatening episodes of fever and dehydration during the early weeks of life, growth retardation, hypercalciuria, and early-onset nephrocalcinosis. Mutations in the bumetanide-sensitive Na-K-2Cl cotransporter (NKCC2) and ATP-sensitive inwardly rectifying potassium channel (ROMK) of the thick ascending limb of Henle's loop have been identified in the antenatal bartter syndrome. We report the identification of two heterozygous mutations of the gene for Kir 1.1 (ROMK) from an antenatal bartter syndrome patient who presented at birth with mild salt wasting and a biochemical findings that mimicked primary pseudohypoaldosteronism type 1, such as hyperkalemia and hyponatremia, and evolved to a relatively benign course. We have identified amino acid exchanges Arg338Stop and Met357Thr in the gene exon 5 for ROMK by PCR and direct sequencing. Both mutations alter the C-terminus of the ROMK protein, and can affect channel function.- - - - - - - - - - ranking = 9keywords = syndrome (Clic here for more details about this article) |
9/25. Erythrocyte transmembrane Na and K fluxes in pseudohypoaldosteronism.pseudohypoaldosteronism (PHA) is a disease characterized by hyponatremia, hypotension, and dehydratation, despite the presence of hyperreninemic hyperaldosteronism. The membrane-bound Na,K ATPase activity and the transmembrane Na and K transport systems have been studied in vitro in red blood cells of two subjects, son and mother, affected by pseudohypoaldosteronism with different degrees of clinical involvement. Both parameters were significantly altered suggesting that the refractory response to mineralocorticoids is detectable, not only in kidneys and salivary and sweat glands, but also in red blood cells. Since pseudohypoaldosteronism, in its asymptomatic form, may be much more common than expected, we suggest the use of the tests described herein as a practical approach to the early diagnosis of pseudohypoaldosteronism in the investigation of sodium wasting syndromes.- - - - - - - - - - ranking = 1keywords = syndrome (Clic here for more details about this article) |
10/25. A novel epithelial sodium channel beta-subunit mutation associated with hypertensive liddle syndrome.Low-renin hypertension responsive to amiloride-thiazide therapy in a 4-year-old Afro-Haitian girl suggested liddle syndrome. urine steroid profiling substantiated the diagnosis and dna analysis of the epithelial sodium channel (ENaC) revealed a novel heterozygous beta ENaC mutation in the patient and in her hypertensive father. liddle syndrome should be considered as a cause of hypertension in young children particularly with suppressed renin activity.- - - - - - - - - - ranking = 6keywords = syndrome (Clic here for more details about this article) |
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