Infants and children with Bartter syndrome present with polyuria and polydipsia, whereas older children present with constipation, salt craving and muscle cramps. The symptomatology is mainly due to renal concentrating defect [1]. This disorder is characterized by hypokalemia, hypochloremia, hypercalciuria, salt wasting with metabolic alkalosis.

A 10-day-old male child born out of third degree consanguineous marriage presented with severe respiratory distress.The antenatal history was uneventful. The neonate was suspected as late-onset sepsis and appropriate management was started. The investigations showed normal counts, C-reactive protein (CRP) levels and urine examination.The condition deteriorated further and required mechanical ventilation. The baby was started on intravenous piperacillin-tazobactam and amikacin, but antibiotics were stopped after 7 days as blood culture sensitivity was negative.

The baby’s condition gradually improved and was weaned from the ventilator after 8 days. Renal parameters, urine output and leucocyte counts were monitored regularly and remained normal. The blood gases were all normal. The child was started on breast feeds on day 32 of life and was under observation for proper feed establishment and weight gain. On day 48, the infant developed decreased urine output along with respiratory distress for second time. Investigations showed normal leucocyte counts and normal CRP levels but renal parameters were suggestive of intrinsic renal failure. Peritoneal dialysis and non-invasive ventilation were started. The condition of the child improved and he was weaned from ventilator after 4 days. The renal parameters normalized after 20 cycles of dialysis.Blood and urine cultures were negative.Post-dialysis the child developed polyuria with a daily urine output >8 mL/kg/day. The infant continued to have polyuria inspite of measures to decrease urine output. The infant developed metabolic alkalosis despite acute kidney injury and polyuria. The blood pressures were in normal range. The urine examination showed, red blood cells, granular casts and proteinuria. Urinary electrolytes values showed urine osmolality – 133.2 mOsm/kg (normal 500 – 850 mOsm/kg), urinary chloride–66 mEq/L (normal <10 mEq/L), and spot calcium creatinine ratio - 2.96:1.0 (normal <0.86:1). Serum calcium,vitamin D and parathyroid hormone levels were within normal range. Ultrasonography of kidney and bladder showed calcifications in apex of medullary pyramids suggesting bilateral medullary nephrocalcinosis. We diagnosed our case as type 2 Bartter syndrome.

The classical Bartter syndrome (type 3) is perinatal in onset and presents with polyhydramnios, neonatal salt wasting and recurrent episodes of dehydration. Antenatal Bartter syndrome (type 1,2 and 4) typically manifests in infancy with severe phenotype compared to the classical syndrome [2]. The biochemical features reflect defect in sodium, chloride and potassium transporter on ascending limb of loop of Henle [3].

Various genes are associated with Bartter syndrome [4]; MAGED2 mutation described recently is associated with transient Bartter syndrome which starts antenatally with severe phenotype and usually resolves by six weeks of age. Our case presented at around six weeks with acute kidney injury without hypomagnesemia [5]. The diagnosis of Bartter syndrome in neonate or infant is suggested by severe hypokalemia, hypochloremia and metabolic alkalosis. Hypercalciuria is typical and nephrocalcinosis is seen resulting from hyper-calciuria in type 1 and 2. Hypomagnesemia is seen in minority. Urinary levels of chloride are also very much elevated which helps in differentiating this picture from chronic vomiting and cystic fibrosis. The tubular defect in Bartter or Gittlemann syndrome cannot be corrected [6], but with careful fluid and electrolyte management, long term prognosis is good. We treated the child with proper fluid and electrolyte correction following which hyperkalemia improved. The potassium levels normalised after a period of eight days without any therapy for potassium corrections except for restriction. Urinary electrolytes continued to remain elevated. The child was discharged in a stable condition after establishing oral feeds.

The child followed-up with us two weeks after the discharge which was uneventful. Our case focuses light on the rare presentation of Bartter syndrome with acute kidney injury probably due to nephrocalcinosis which might have started in utero.

1. Sinha A, Bagga A. Tubular disorders. In: Srivastava RN, Bagg A, editors. Pediatric Nephrology, 6th edition. Jaypee publishers; 2016. p. 312-16.

2. Dixon BP, Bartter syndrome, inherited tubular transport abnormalities. In: Kliegman, St Geme, Blum, Shah, Tasker, Wilson, editors. Nelsons Textbook of Paediatrics, 21st edition. Elsiever; 2019. p. 2767-9.

3. Kurtz I. Molecular pathogenesis of Bartter’s and Gitelman’s syndromes. Kidney Int.　1998;54:1396-410.

4. Simon DB, Karet FE, Rodriguez-Soriano J, Hamdan JH, DiPietro A, Trachtman H, et al. Genetic heterogeneity of Bartter’s syndrome revealed by mutations in the K+ channel, ROMK: Classic diseases revisited. Nat Genet.　1996;14:152-6.

5. Laghmani K, Beck BB, Yang SS, Seaayfan E, Wenzel A, Reusch B, et al.　Polyhydramnios, transient antenatal Bartter’s syndrome, and MAGED2 mutations: N Engl J Med. 2016;374:1853-63.

6. Fujita T, Ando K, Sato Y, Yamashita K, Nomura M, Fukui T. Independent roles of prostaglandins and the renin-angiotensin system in abnormal vascular reactivity in Bartter’s syndrome. Am J Med. 1982;73:71-6.