title: A patient with Dent disease and features of Bartter syndrome caused by a novel mutation of CLCN5.
abstract: Dent disease is an X-linked tubulopathy mainly caused by inactivating mutations of CLCN5. Features of Bartter syndrome such as hypokalemic metabolic alkalosis are rarely observed in patients with Dent disease. We report a Japanese male patient with Dent disease who also manifested features of Bartter syndrome. At the age of 3 years, he was diagnosed with Dent disease based on low molecular weight proteinuria and hypercalciuria. One year later, he was found to have features of Bartter syndrome, i.e., hypokalemia and metabolic alkalosis, and high levels of plasma renin activity and aldosterone with a normal blood pressure. Despite medical interventions, he developed chronic kidney disease stage 3 at the age of 21 years. To investigate the molecular basis of his disease, CLCN5, KCNJ1, SLC12A1, and CLCkb were analyzed and a novel mutation (Y567X) in CLCN5 was identified.
  
  
  CONCLUSIONS
  Hypokalemic metabolic alkalosis is a rare manifestation in Dent disease. It is speculated that Dent patients with features of Bartter syndrome are susceptible to progression to renal failure. To study this hypothesis, additional observations and long-term follow-up of such patients are necessary.
authors.affiliation: Department of Pediatrics, Hokkaido University Graduate School of Medicine, N15, W7, Sapporo 060-8638, Japan. okamon@med.hokudai.ac.jp
authors.forename: Takayuki
authors.initials: T
authors.lastname: Okamoto
authors.forename: Toshihiro
authors.initials: T
authors.lastname: Tajima
authors.forename: Tomoya
authors.initials: T
authors.lastname: Hirayama
authors.forename: Satoshi
authors.initials: S
authors.lastname: Sasaki
mesh_terms: D000015:Abnormalities, Multiple / Q000235:genetics*; D001477:Bartter Syndrome / Q000175:diagnosis / Q000235:genetics*; D002675:Child, Preschool; D018118:Chloride Channels / Q000235:genetics*; D018389:Codon, Nonsense; D057973:Dent Disease / Q000175:diagnosis / Q000235:genetics*; D006801:Humans; D008297:Male
chemical_list: C097503:CLC-5 chloride channel; D018118:Chloride Channels; D018389:Codon, Nonsense