Snapshot A 5-year-old boy is brought to the pediatrician for muscle aches and pains. He denies any recent trauma. On review of systems, he endorses increased thirst and increased urinary frequency. Laboratory exam reveals hypomagnesemia and normal potassium. His urine studies show decreased calcium. He is sent home on magnesium supplements and plans for future genetic testing. Introduction Clinical definition login to view 5 more bullets Epidemiology Incidence login to view 2 more bullets Demographics login to view 1 more bullet Risk factors login to view 1 more bullet Etiology Pathogenesis login to view 2 more bullets Genetics login to view 5 more bullets Presentation Symptoms login to view 7 more bullets Physical exam login to view 1 more bullet Studies Labs login to view 5 more bullets Urine studies login to view 1 more bullet Differential Bartter’s syndrome login to view 1 more bullet Renal Tubular DefectsCategoryFanconi SyndromeBartter SyndromeGitelman SyndromeLiddle SyndromeDefect localizationProximal tubuleThick ascending loop of HenleDistal convoluted tubuleCollecting tubuleEtiologyWilson diseaseTyrosinemiaCystinosisMultiple myelomaGalactosemiaMitochondrial myopathiesMedicationsaminoglycosidescisplatinifosfamidevalproic acidHeavy metalsmercuryleadAutosomal recessive mutation involving the NKCC2 cotransporterAutosomal recessive mutationinvolving the NaCl cotransporterAutosomal dominant mutation leading to increased activity of epithelial Na+ channel (ENaC)FindingsHypophosphatemiaAminoaciduriaRenal glucosuriaTubular proteinuriaProximal renal tubular acidosisHypokalemiaHypochloremiaMetabolic alkalosisNormotensionElevated plasma renin levelHypokalemiaHypochloremiaMetabolic alkalosisHypomagnesemiaHypocalciuriaNormotensionHypertensionHypokalemiaMetabolic alkalosis Treatment Conservative login to view 3 more bullets Medical login to view 12 more bullets Complications Cardiac arrhythmia due to hypomagnesemia and hypokalemia Chondrocalcinosis