DOI QR코드

DOI QR Code

A novel mutation of CLCNKB in a Korean patient of mixed phenotype of Bartter-Gitelman syndrome

  • Cho, Hee-Won (Department of Pediatrics, Samsung Medical Center, Sungkyunkwan University School of Medicine) ;
  • Lee, Sang Taek (Department of Pediatrics, Samsung Medical Center, Sungkyunkwan University School of Medicine) ;
  • Cho, Heeyeon (Department of Pediatrics, Samsung Medical Center, Sungkyunkwan University School of Medicine) ;
  • Cheong, Hae Il (Department of Pediatrics, Seoul National University Children's Hospital)
  • 투고 : 2015.11.25
  • 심사 : 2016.01.27
  • 발행 : 2016.11.15

초록

Bartter syndrome (BS) is an inherited renal tubular disorder characterized by low or normal blood pressure, hypokalemic metabolic alkalosis, and hyperreninemic hyperaldosteronism. Type III BS is caused by loss-of-function mutations in CLCNKB encoding basolateral ClC-Kb. The clinical phenotype of patients with CLCNKB mutations has been known to be highly variable, and cases that are difficult to categorize as type III BS or other hereditary tubulopathies, such as Gitelman syndrome, have been rarely reported. We report a case of a 10-year-old Korean boy with atypical clinical findings caused by a novel CLCNKB mutation. The boy showed intermittent muscle cramps with laboratory findings of hypokalemia, severe hypomagnesemia, and nephrocalcinosis. These findings were not fully compatible with those observed in cases of BS or Gitelman syndrome. The CLCNKB mutation analysis revealed a heterozygous c.139G>A transition in exon 13 [p.Gly(GGG)465Glu(GAG)]. This change is not a known mutation; however, the clinical findings and in silico prediction results indicated that it is the underlying cause of his presentation.

키워드

참고문헌

  1. Bartter FC, Pronove P, Gill JR Jr, Maccardle RC. Hyperplasia of the juxtaglomerular complex with hyperaldosteronism and hypokalemic alkalosis. A new syndrome. Am J Med 1962;33:811-28. https://doi.org/10.1016/0002-9343(62)90214-0
  2. Schurman SJ, Perlman SA, Sutphen R, Campos A, Garin EH, Cruz DN, et al. Genotype/phenotype observations in African Americans with Bartter syndrome. J Pediatr 2001;139:105-10. https://doi.org/10.1067/mpd.2001.115020
  3. Lee BH, Cho HY, Lee H, Han KH, Kang HG, Ha IS, et al. Genetic basis of Bartter syndrome in Korea. Nephrol Dial Transplant 2012;27:1516-21. https://doi.org/10.1093/ndt/gfr475
  4. Ohkubo K, Matsuzaki T, Yuki M, Yoshida R, Terawaki Y, Maeyama A, et al. A novel mutation of CLCNKB in a Japanese patient of Gitelman-like phenotype with diuretic insensitivity to thiazide administration. Meta Gene 2014;2:342-8. https://doi.org/10.1016/j.mgene.2014.04.005
  5. Nozu K, Iijima K, Kanda K, Nakanishi K, Yoshikawa N, Satomura K, et al. The pharmacological characteristics of molecular-based inherited salt-losing tubulopathies. J Clin Endocrinol Metab 2010;95:E511-8. https://doi.org/10.1210/jc.2010-0392
  6. Konrad M, Hou J, Weber S, Dotsch J, Kari JA, Seeman T, et al. CLDN16 genotype predicts renal decline in familial hypomagnesemia with hypercalciuria and nephrocalcinosis. J Am Soc Nephrol 2008;19:171-81. https://doi.org/10.1681/ASN.2007060709
  7. Praga M, Vara J, Gonzalez-Parra E, Andres A, Alamo C, Araque A, et al. Familial hypomagnesemia with hypercalciuria and nephrocalcinosis. Kidney Int 1995;47:1419-25. https://doi.org/10.1038/ki.1995.199
  8. Konrad M, Schaller A, Seelow D, Pandey AV, Waldegger S, Lesslauer A, et al. Mutations in the tight-junction gene claudin 19 (CLDN19) are associated with renal magnesium wasting, renal failure, and severe ocular involvement. Am J Hum Genet 2006;79:949-57. https://doi.org/10.1086/508617
  9. Hanssen O, Castermans E, Bovy C, Weekers L, Erpicum P, Dubois B, et al. Two novel mutations of the CLDN16 gene cause familial hypomagnesaemia with hypercalciuria and nephrocalcinosis. Clin Kidney J 2014;7:282-5. https://doi.org/10.1093/ckj/sfu019
  10. Andrini O, Keck M, Briones R, Lourdel S, Vargas-Poussou R, Teulon J. ClC-K chloride channels: emerging pathophysiology of Bartter syndrome type 3. Am J Physiol Renal Physiol 2015;308:F1324-34. https://doi.org/10.1152/ajprenal.00004.2015
  11. Zelikovic I, Szargel R, Hawash A, Labay V, Hatib I, Cohen N, et al. A novel mutation in the chloride channel gene, CLCNKB, as a cause of Gitelman and Bartter syndromes. Kidney Int 2003;63:24-32. https://doi.org/10.1046/j.1523-1755.2003.00730.x
  12. Jeck N, Konrad M, Peters M, Weber S, Bonzel KE, Seyberth HW. Mutations in the chloride channel gene, CLCNKB, leading to a mixed Bartter-Gitelman phenotype. Pediatr Res 2000;48:754-8. https://doi.org/10.1203/00006450-200012000-00009
  13. Xiumin W, Zheng S, Meichun X, Junfen F, Li L. A Chinese girl with Bartter syndrome type III due to a novel mutation and/or single nucleotide polymorphisms (SNPs) in CLCNKB gene. Iran J Pediatr 2013;23:89-94.