title: Molecular analysis of the CLCNKB gene in Japanese patients with classic Bartter syndrome.
abstract: Deletions or mutations in the gene encoding the basolateral chloride channel CLC-Kb (CLCNKB) cause classic Bartter syndrome (MIM 602023), which is characterized by hypokalemic metabolic alkalosis, hyperreninemic hyperaldosteronism and hypercalciura. These patients are usually diagnosed during infancy or childhood due to failure to thrive and growth retardation. The purpose of this study was to investigate the underlying mutations in Japanese patients with classic Bartter syndrome. Seven Japanese patients from seven different families diagnosed as having classic Bartter syndrome were studied. Analysis of CLCNKB demonstrated a large deletion in two patients, a partial deletion in one patient and two mutations (DeltaL130 in exon 4 and W610X in exon 16) in the remaining four patients. DeltaL130 is a novel mutation, but W610X was previously reported in three unrelated Japanese patients. Six out of the seven patients were diagnosed due to typical characteristics of classic Bartter syndrome such as failure to thrive and poor weight gain however, one patient was asymptomatic with mild hypokalemia. In conclusion, we identified a novel mutation of the CLCNKB gene, DeltaL130. We did not determine whether the W610X mutation in our patients was from a common ancestor or if this mutation is frequent in Japan.
authors.affiliation: Department of Pediatrics, Hokkaido University School of Medicine, Sapporo, Japan.
authors.forename: Toshihiro
authors.initials: T
authors.lastname: Tajima
authors.forename: Mitsuru
authors.initials: M
authors.lastname: Nawate
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Takahashi
authors.forename: Yumiko
authors.initials: Y
authors.lastname: Mizoguchi
authors.forename: Shigetaka
authors.initials: S
authors.lastname: Sugihara
authors.forename: Masaaki
authors.initials: M
authors.lastname: Yoshimoto
authors.forename: Mutsumi
authors.initials: M
authors.lastname: Murakami
authors.forename: Masanori
authors.initials: M
authors.lastname: Adachi
authors.forename: Katsuhiko
authors.initials: K
authors.lastname: Tachibana
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Mochizuki
authors.forename: Kenji
authors.initials: K
authors.lastname: Fujieda
mesh_terms: D044466:Asian People / Q000235:genetics; D001477:Bartter Syndrome / Q000235:genetics*; D002675:Child, Preschool; D018118:Chloride Channels / Q000235:genetics*; D004252:DNA Mutational Analysis; D006801:Humans; D007223:Infant; D009154:Mutation
chemical_list: C412733:CLCNKB protein, human; D018118:Chloride Channels