Department of Human Genetics, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands,
Orphanet Journal of Rare Diseases 2008, 3:22doi:10.1186/1750-1172-3-22
Nine VAM Knoers and Elena N Levtchenko,
The electronic version of this article is the complete one and can be found online at: http://www.ojrd.com/content/3/1/22
© 2008 Knoers and Levtchenko; licensee BioMed Central Ltd.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Gitelman syndrome (GS), also referred to as familial hypokalemia-hypomagnesemia, is characterized by hypokalemic metabolic alkalosis in combination with significant hypomagnesemia and low urinary calcium excretion. The prevalence is estimated at approximately 1:40,000 and accordingly, the prevalence of heterozygotes is approximately 1% in Caucasian populations, making it one of the most frequent inherited renal tubular disorders. In the majority of cases, symptoms do not appear before the age of six years and the disease is usually diagnosed during adolescence or adulthood.
Index of suspicion. Case 3. Hypokalemic periodic paralysis
This section of Pediatrics in Review reminds clinicians of those conditions that can present in a misleading fashion and require suspicion for early diagnosis. Emphasis has been placed on conditions in which early diagnosis is important and that the general pediatrician might be expected to encounter, at least once in a while.
By Shawna Kopchu R.N.
Hypokalemia refers to a below normal serum potassium concentration. It usually indicates a real deficit in total potassium stores; however, it may occur in patients having normal potassium stores when alkalosis is present (since alkalosis causes a temporary shift of serum potassium into the cells).
Hypokalemia is frequently encountered in clinical medicine and has been estimated to occur in approximately 20% of patients admitted to general internal medicine service. Symptoms may be absent, identified only on routine electrolyte screening, or may range from neuromuscular weakness, rarely progressing to frank paralysis or sudden cardiac death. Usually correction of hypokalemia is not difficult, but if therapy is not appropriate, symptoms may worsen with potentially severe, even lethal, consequences.
Gitelman disease associated with growth hormone deficiency, disturbances in vasopressin secretion and empty sella: a new hereditary renal tubular-pituitary syndrome?
Gitelman disease was diagnosed in two unrelated children with hypokalemic metabolic alkalosis and growth failure (a boy and a girl aged 7 mo and 9.5 y, respectively, at clinical presentation) on the basis of mutations detected in the gene encoding the thiazide-sensitive NaCl cotransporter of the distal convoluted tubule. GH deficiency was demonstrated by specific diagnostic tests in both children. Hypertonic saline infusion tests showed a partial vasopressin deficiency in the girl and delayed secretion of this hormone in the boy.
Impaired response to furosemide in Hyperprostaglandin E syndrome: Evidence for a tubular defect in the loop of Henle
In hyperprostaglandin E syndrome (HPS) renal wasting of electrolytes and water is consistently associated with enhanced synthesis of prostaglandin E2 . In contrast to Bartter or Gitelman syndrome (BS/GS), HPS is characterized by its severe prenatal manifestation, leading to fetal polyuria, development of polyhydramnios, and premature birth. This disorder mimics furosemide treatment with hypokalemic alkalosis, hypochloremia, isosthenuria, and impaired renal conservation of both calcium and magnesium. Therefore the thick ascending limb of the loop of Henle seems to be involved in HPS.
Evidence for Disturbed Regulation of Calciotropic Hormone Metabolism in Gitelman Syndrome
Little attention has been paid to interactions between circulating levels of calcium, PTH, and 1,25-dihydroxycholecalciferol [1,25(OH)2 D] and bone mineral density in primary renal magnesium deficiency. Plasma and urinary electrolytes, and circulating levels of calciotropic hormones were studied in 13 untreated patients with primary renal tubular hypokalemic alkalosis with hypocalciuria and magnesium deficiency. The blood ionized calcium concentration was significantly lower in patients than in controls.
It is now evident that the term Bartter syndrome does not represent a unique entity but encompasses a variety of disorders of renal electrolyte transport. Application of molecular biology techniques has permitted a better understanding of these “Bartter-like syndromes,” which at present can be divided into three different genetic and clinical entities.
Bartter syndrome is characterized by hyperplasia of the renal juxtaglomerular apparatus, hyperaldosteronism, and hypokalemic alkalosis. We report a case of Bartter syndrome associated with normal serum calcium levels and posterior choroidal calcification.
We have followed four patients with Bartter syndrome for a mean of 25.4 years (range 21.5-28.8 years) after diagnosis. All patients received non-steroidal anti-inflammatory drugs (NSAID). In all patients, various degrees of renal dysfunction were noted to be temporally associated with NSAID therapy. In two patients, renal dysfunction resolved after discontinuing NSAID therapy, while maintaining other chronic medications such as potassium-sparing diuretics. Renal dysfunction persisted after NSAID withdrawal in two patients. We report these cases as a warning that NSAID should be considered an important cause of either reversible or irreversible renal dysfunction in Bartter syndrome.
Pediatr Nephrol 1998 Nov;12(9):775-7, Schachter AD, Arbus GS, Alexander RJ, Balfe JW
Department of Pediatrics, The Hospital for Sick Children and University of Toronto, Ontario, Canada.
PMID: 9874326, UI: 99089722
To describe prenatal genetic diagnosis in hyperprostaglandin E syndrome (HPS) and the effect of indomethacin therapy on the course of the disease before birth and in the neonatal period.