LAUSR

A 6-month-old girl was admitted to another hospital with the complaints of failure to thrive, intermittent vomiting, and polyuria. She was born at full-term with a birth weight of 2710 g to first-degree consanguineous parents. Pregnancy history was negative for oligo/polyhydramnios. Her firstdegree cousin had chronic kidney disease with neurodevelopmental retardation. The patient, who was only breastfed for the first 6 months, had body weight and height of 6100 g (− 1.6 SDS) and 63 cm (− 1.31 SDS) at 6 months of age, respectively. On physical examination, she was normotensive with a blood pressure (BP) of 88/48 mmHg (72nd and 86th percentiles for systolic and diastolic BP, respectively). Decreased skin turgor and tachycardia were noted. Genital characteristics were compatible with her age and gender. Laboratory analysis revealed hypokalemic metabolic alkalosis with normal kidney functions. Sweat test and genetic analysis were normal for cystic fibrosis. Abdominal ultrasonography (USG) was unremarkable. She had increased urine output (7.4 mL/kg/h) and hypercalciuria (calcium/ creatinine: 1.44 mg/mg on spot urine). Urinary system USG showed medullary nephrocalcinosis. With the diagnosis of Bartter syndrome, oral potassium supplementation (3 mEq/ kg/d), and indomethacin (1 mg/kg/d) were commenced. During the follow-up, doses of the medications were increased due to persistence of the clinical and laboratory findings. Besides, she had several hospitalizations for severe hypokalemia. The patient, who had normal genetic analysis for antenatal Bartter syndrome, was referred to our hospital at 2.5 years of age for further investigation. At that time, she still had polyuria and deterioration in body weight and height as 10.0 kg (− 2.15 SDS) and 81.0 cm (− 2.66 SDS). BP was 90/50 mmHg (65th and 68th percentiles for systolic and diastolic BP, respectively). Physical examination was particularly remarkable for dysmorphic facial features including a coarse facial appearance with a wide nose and a flat nasal bridge, a wide mouth with thick lips, and thick eyebrows. The scalp hair was sparse and the 5th distal phalanges of both hands were shorter than normal. Mild delay in neurodevelopmental steps was noted. Brain magnetic resonance imaging (MRI) showed 12 × 7.5 × 8.5-mm cyst in the pineal gland and a venous angioma extending into the parietal white matter. Electroencephalography (EEG) monitoring revealed spike wave discharges more frequently in the right temporal region. In laboratory analysis, hypokalemia (serum potassium: 3.09 mmol/L), metabolic alkalosis (pH: 7.50, HCO3: 31.1 mmol/L), hypercalciuria (calcium/creatinine: 0.48 mg/mg on spot urine) with normal serum glucose (92 mg/dl), creatinine (0.36 mg/dL), chloride (104 mmol/L), and magnesium levels (2.1 mg/dL) were detected. Urine examination revealed specific gravity of 1006, pH: 6.5, without hematuria, pyuria, proteinuria, or glycosuria. Spot urine chloride level was in the normal range (20 mmol/L). USG confirmed medullary nephrocalcinosis. Plasma renin activity (0.07 ng/mL.h; normal range: 0.6–4.18) and aldosterone The answers to these questions can be found at http:// doi. org/ 10. 1007/ s0046702205510-8