Bartter's syndrome is a rare hereditary disorder which is characterized by defects in renal salt handling, that result in hypokalemia, metabolic alkalosis and hypercalciuria. It commonly presents in neonates with vomiting, dehydration and failure to thrive. However, we reported an uncommon presentation of Bartter's syndrome in a boy, who mainly suffered from polyuria, frequency and urgency.

This case was reported from a tertiary care center. The patient was subjected to clinical, laboratory and radiological evaluation to establish the diagnosis. Combined urological and nephrological management was advocated. The patient was then followed up after 6 months.

A 4-year-old boy presented to the pediatric urology clinic with polyuria, frequency, urgency and occasional episodes of nocturnal enuresis. Physical examination showed characteristic facies of triangular face, prominent forehead and large eyes with signs of dehydration (Figure 1). Laboratory investigations showed hypokalemia, metabolic alkalosis, hypochloremia and hypercalciuria. Renal and bladder ultrasonography (RBUS) revealed bilateral G II hydronephrosis (HN) with bright echogenic foci in the medulla suggestive of medullary nephrocalcinosis with hugely distended bladder (Figure 1). Magnetic resonance urography (MRU) also showed bilateral hydroureteronephrosis with huge bladder, whereas voiding cystourethrogram (VCUG) revealed markedly increased bladder capacity with smooth outline and free urethral flow of urine without vesicoureteral reflux on either side or post-void residual urine (PVR), as shown in Figure 2. He was managed by timed and double voiding and monitoring of renal function, HN and PVR. Nephrological management was also performed in terms of potassium supplementation, monitoring of hydration status and urine output. Follow-up after 6 months showed preserved renal function, no progression in HN and insignificant PVR by RBUS and reduction in bladder capacity by VCUG (Figure 3).

We reported a case of undiagnosed Bartter's syndrome, who presented with polyuria, frequency, urgency, nocturnal enuresis and characteristic facies of triangular face, prominent forehead and large eyes with signs of dehydration. His laboratory investigations showed hypokalemia, metabolic alkalosis, hypochloremia and hypercalciuria. His radiological images also revealed bilateral G II HN and medullary nephrocalcinosis with hugely distended bladder and free urethral flow of urine without vesicoureteral reflux on either side or significant PVR. He received both urological and nephrological management. Six months later, he had preserved renal function, no progression in HN, insignificant PVR and reduction in bladder capacity.

Voiding dysfunction may occur as a result of any condition that leads to polyuria, such as Bartter's syndrome and it could be an atypical presentation for such patients. High index of suspicion for Bartter's syndrome should be maintained in children with unexplained voiding dysfunction and persistent hypokalemia.