Snapshot A 3-year-old boy is brought to the pediatrician due poor growth and increased urinary frequency. According to the mother, the child appears to be very thirsty. He was born prematurely and the mother states she was found to have polyhydramnios on ultrasonograpahy while pregnant. Laboratory testing is significant for hypokalemia, hypochloremia, mild hypomagnesemia, and metabolic alkalosis. Introduction Clinical definition login to view 6 more bullets Epidemiology login to view 11 more bullets Pathophysiology login to view 4 more bullets Genetics login to view 2 more bullets Prognosis login to view 1 more bullet Presentation Symptoms login to view 5 more bullets Physical exam login to view 3 more bullets Studies Labs login to view 4 more bullets Differential Diuretic abuse Gitleman syndrome Surreptitious vomiting Mineralocorticoid excess Cystic fibrosis Renal Tubular Defects Category Fanconi Syndrome Bartter Syndrome Gitelman Syndrome Liddle Syndrome Defect localization Proximal tubule Thick ascending loop of Henle Distal convoluted tubule Collecting tubule Etiology Wilson disease Tyrosinemia Cystinosis Multiple myeloma Galactosemia Mitochondrial myopathies Medications aminoglycosides cisplatin ifosfamide valproic acid Heavy metals mercury lead Autosomal recessive mutation involving the NKCC2 cotransporter Autosomal recessive mutation involving the Na+Cl- cotransporter Autosomal dominant mutation leading to increased activity of epithelial sodium channel (ENaC) Findings Hypophosphatemia Aminoaciduria Renal glucosuria Tubular proteinuria Proximal renal tubular acidosis Hypokalemia Hypochloremia Metabolic alkalosis Normotension Elevated plasma renin level Hypokalemia Hypochloremia Metabolic alkalosis Hypomagnesemia Hypocalciuria Normotension Hypertension Hypokalemia Metabolic alkalosis Treatment Medical login to view 16 more bullets Complications Cardiac arrhythmia due to severe hypokalemia