title: Mimicry of surreptitious diuretic ingestion and the ability to make a genetic diagnosis.
abstract: Gitelman's syndrome, also known as "hypocalciuric variant of Bartter's syndrome", is a cause of chronic hypokalemia and hypomagnesemia in adults. A specific gene has been found responsible for this disorder, encoding the thiazide-sensitive NaCl coporter (TSC) in the distal convoluted tubule. We describe a psychiatric patient with chronic symptomatic hypokalemia and hypomagnesemia whose electrolyte disturbances were subsequently misdiagnosed as an acute alcohol and benzodiazepine withdrawal syndrome, as chronic diuretic abuse and as a classical Bartter's syndrome. Finally, genetic investigation revealed the presence of mutations in the SLC12A3 gene leading to the proper diagnosis of Gitelman's syndrome. We emphasize that Gitelman's syndrome should be suspected in every hypokalemic patient with biochemical resemblance of diuretic ingestion, especially when repeated toxic screens for diuretics are negative. The ability to make a molecular-genetic diagnosis can be of practical benefit in confusing clinical settings.
authors.affiliation: Department of Internal Medicine, University Hospital Gent, Belgium. katrien.vanrenterghem@rug.ac.be
authors.forename: H
authors.initials: H
authors.lastname: Schepkens
authors.forename: H
authors.initials: H
authors.lastname: Hoeben
authors.forename: R
authors.initials: R
authors.lastname: Vanholder
authors.forename: N
authors.initials: N
authors.lastname: Lameire
mesh_terms: D000328:Adult; D001477:Bartter Syndrome / Q000175:diagnosis / Q000235:genetics; D001581:Benzothiadiazines; D002118:Calcium / Q000652:urine*; D002352:Carrier Proteins / Q000235:genetics; D003951:Diagnostic Errors; D004232:Diuretics; D006801:Humans; D007008:Hypokalemia / Q000175:diagnosis / Q000235:genetics*; D008274:Magnesium / Q000097:blood*; D008297:Male; D017354:Point Mutation; D012965:Sodium Chloride / Q000378:metabolism; D049993:Sodium Chloride Symporter Inhibitors / Q000009:adverse effects*; D049992:Sodium Chloride Symporters; D013375:Substance Withdrawal Syndrome / Q000175:diagnosis; D019966:Substance-Related Disorders / Q000175:diagnosis*; D027981:Symporters; D013577:Syndrome
chemical_list: D001581:Benzothiadiazines; D002352:Carrier Proteins; D004232:Diuretics; D049993:Sodium Chloride Symporter Inhibitors; D049992:Sodium Chloride Symporters; D027981:Symporters; D012965:Sodium Chloride; D008274:Magnesium; D002118:Calcium