title: A rare case of Gitelman's syndrome presenting with hypocalcemia and osteopenia.
abstract: Gitelman's syndrome (GS), an autosomal recessive disorder caused by a defect of the thiazide-sensitive Na-Cl cotransporter (TSC) at the distal tubule, is characterized by hyperreninemic hyperaldosteronism with normal or low blood pressure, hypokalemia, metabolic alkalosis, hypomagnesemia and hypocalciuria. An 18-yr-old Japanese man was admitted to our hospital with a history of muscle weakness and transient tetanic episodes. He showed hypocalcemia in addition to hypokalemia, severe hypomagnesemia, hypocalciuria and hyperreninemic hyperaldosteronism with normal blood pressure. Furthermore, bone mineral density at the lumbar spine revealed osteopenia. A diagnosis of GS was made on the basis of clinical features, laboratory data and renal function test. The electrolyte imbalance was corrected and bone mineral density was slightly increased with chronic treatment of magnesium and potassium salts. Genetic analysis revealed that TSC gene of the patient has a heterozygous C to A nucleotide substitution at position 545 in exon 4, which causes a threonine (Thr) to lysine (Lys) substitution at position 180. This is a rare case of GS with hypocalcemia and osteopenia which could be caused by severe hypomagnesemia.
authors.affiliation: Department of Medicine II, Hokkaido University Graduate School of Medicine, Sapporo, Japan.
authors.forename: A
authors.initials: A
authors.lastname: Nakamura
authors.forename: C
authors.initials: C
authors.lastname: Shimizu
authors.forename: S
authors.initials: S
authors.lastname: Nagai
authors.forename: S
authors.initials: S
authors.lastname: Taniguchi
authors.forename: M
authors.initials: M
authors.lastname: Umetsu
authors.forename: T
authors.initials: T
authors.lastname: Atsumi
authors.forename: N
authors.initials: N
authors.lastname: Yoshioka
authors.forename: Y
authors.initials: Y
authors.lastname: Ono
authors.forename: T
authors.initials: T
authors.lastname: Tajima
authors.forename: M
authors.initials: M
authors.lastname: Kubo
authors.forename: T
authors.initials: T
authors.lastname: Koike
mesh_terms: D000293:Adolescent; D001477:Bartter Syndrome / Q000150:complications* / Q000175:diagnosis* / Q000235:genetics; D001851:Bone Diseases, Metabolic / Q000209:etiology*; D003937:Diagnosis, Differential; D006801:Humans; D006996:Hypocalcemia / Q000209:etiology*; D008297:Male; D009154:Mutation; D011955:Receptors, Drug / Q000235:genetics*; D049992:Sodium Chloride Symporters; D064486:Solute Carrier Family 12, Member 3; D027981:Symporters / Q000235:genetics*; D013577:Syndrome
chemical_list: D011955:Receptors, Drug; C578874:SLC12A3 protein, human; D049992:Sodium Chloride Symporters; D064486:Solute Carrier Family 12, Member 3; D027981:Symporters; C064415:thiazide receptor