https://imcjms.com Ibrahim Medical College Journal of Medical Science https://imcjms.com/registration/journal_full_text/222 Thu, 18 May 2017 10:04:33 +0000 Gitelman’s syndrome is an autosomal recessive disorder caused by a defect of the thiazide-sensitive sodium chloride co-transporter at the distal tubule, characterized by hypomagnesemia, hypokalemic alkalosis and hypocalciuria. We report a case of Gitlman’s syndrome in a 44 years old female patient who presented with generalized muscle weakness and carpal spasm and characteristic electrolyte abnormalities. This condition is sometimes confused with Bartter’s syndrome. Address for Correspondence:Dr. Md. Zahid Alam, Junior consultant, Department of Cardiology (Room: 813), BIRDEM Hospital, 122 Kazi Nazrul Islam Avenue, Shahbagh, Dhaka-1000, email: ilazybear@yahoo.com   Gitelman’s syndrome is an autosomal recessive disorders with characteristic metabolic abnormalities which are hypokalemia, metabolic alkalosis, hyperreninemia, hyperplasia of the juxtaglomerular apparatus, hyperaldosteronism and in some patients, hypomagnesemia.1-3 It is usually confused with Bartter’s syndrome and primary hyperaldosteronism. However, Gitelman’s syndrome is usually not present until adulthood and has hypocalciuria which are opposite features of Bartter’s syndrome. Gitelman’s syndrome also differs from primary hyperaldosteronism in two ways – the patients are not hypertensive and the plasma renin activity is increased which is not suppressed by aldosterone induced volume expansion.4,5 The estimated prevalence is approximately 1 per 40,000.6 It is often not diagnosed until late childhood or even adulthood.2 The dominant features are fatigue, weakness, muscle cramp, polyuria and nocturia.4,7,8 Here we report a case of Gitelman’s syndrome presented with tetany. Case report On examination, she was clinically euvolemic with normal skin turgor and no peripheral edema. Carpal spasm was present with positive Chvostek’s sign. The blood pressure was 110/70 mmHg and pulse rate was 84/ minute. Apart from mildly reduced ankle jerks there was no other neurological deficit or proximal muscle weakness. ECG showed prolong QT interval with hypokalemic changes. Laboratory investigations showed low serum potassium (2.4 meq/L), sodium (119 meq), chloride (75 meq/L), magnesium (0.4 mmol/L) and calcium (6.8 mg/dl). Serum bicarbonate was 28 meq/L while serum urea and creatinine were 12 mg/dl and 0.8 mg/ dl respectively. Blood pH was 7.50. The urinary calcium was subnormal at 18 mg/24 hour while on intravenous calcium supplementation (normal range 250 - 300 mg/24 hour in a high Ca2+ supplement). Urine sodium was 117 mmol/24 hour (40-220 mmol), potassium 22 mmol/24 hour (25-150 mmol) and chloride 115 mmol/24 hour (110-250 mmol). Urine specific gravity and urine osmolality were normal. Thyroid function tests (FT3, FT4, TSH), serum parathyroid and cortisol levels were normal. Ultrasound of the abdomen did not reveal any abnormality. Patient was treated with electrolyte supplement. But she did not recover from hypokalemia until spironolactone (100mg twice daily) was started. Based on the above features, the case was diagnosed as Gitleman’s syndrome. Discussion The tubular defect in sodium chloride transport is thought to initiate initial salt loss leading to mild volume depletion and activation of the renin-angiotensin-aldosterone system. The combination of hyperaldosteronism and increased distal flow, due to the reabsorptive defect, enhance potassium and hydrogen secretion at the secretory sites in the collecting tubules leading to hypokalemia and metabolic alkalosis. Because of the tendency to renal salt wasting, patients with Gitelman’s syndrome have a lower blood pressure than that seen in the general population.14,15 The hypocalciuria of Gitelman’s syndrome suggests the involvement of the distal convoluted tubule, where reduced chloride absorption is associated with augmented calcium absorption.16   1.   Stein JH. The pathogenetic spectrum of Bartter’s syndrome. Kidney Int 1985; 28: 85. 3.   Kurtz I. Molecular pathogenesis of Bartter’s and Gitelman’s syndromes. Kidney Int 1998; 54: 1396. 5.   Umami V, Oktavia D, Kunmartini S, Wibisana D, Siregar P. Diagnosis and Clinical Approach in Gitelman’s Syndrome. Acta Med Indones 2011; 43(1): 53-8. 7.   Monnens L, Bindels R, Grunfeld JP. Gitelman syndrome comes of age (editorial). Nephrol Dial Transplant 1998; 13: 1617. 9.   Barakat AJ, Rennert OM. Gitelman’s syndrome (familial hypokalemia- hypomagnesemia). J Nephrol 2001; 14: 43-7. 11.Nakamura A, Shimizu C, Nagai S. A rare case of Gitelman’s syndrome presenting with hypocalcemia and osteopenia. J Endocrinol Invest 2005; 28: 464-8. 13.Al-Ali N, Al-Sayed A, Ramadan A. A Case of Gitelman’s Syndrome Presenting with Hypocalcemia. Kuwait Medical Journal 2008; 40(1): 67-9. 15.Fujita T, Ando K, Sato Y. Independent roles of prostaglandins and the renin-angiotensin system in abnormal vascular reactivity in Bartter’s syndrome. Am J Med 1982; 73: 71. 17.Robson WL, Arbus GS, Balfe JW. Bartter’s syndrome. Am J Dis Child 1979; 133: 636-8. 2026 Ibrahim Medical College. All rights reserved.