A novel compound heterozygous mutation of Gitelman's syndrome in Japan, as diagnosed by an extraordinary response of the fractional excretion rate of chloride in the trichlormethiazide loading test.
Gitelman's syndrome (GS), an inherited disorder due to loss of function of ion channels and transporters such as Na-Cl co-transporter (NCCT) in distal convoluted tubules, is characterized by hypokalemia, hypomagnesemia, hypocalciuria, metabolic alkalosis and hyperreninemic-hyperaldosteronism. A 39-year-old man was admitted to our hospital because of muscle weakness with such intractable disorders. We performed a thiazide-loading test, which revealed a poor response of the fractional excretion rate of chloride compared to healthy subjects. Based on these data, the clinical diagnosis of GS was made. Gene-sequencing analysis revealed compound heterozygous mutations of c.539C > A and c.1844C > T in SLC12A3, which is newly reported in Japanese GS.
Department of Nephrology and Endocrinology, University of Tokyo School of Medicine, Japan. koueda-tky@umin.net
Kohei
K
Ueda
Noriko
N
Makita
Hiroo
H
Kawarazaki
Takayuki
T
Fujiwara
Satoshi
S
Unuma
Toshiaki
T
Monkawa
Matsuhiko
M
Hayashi
Toshiro
T
Fujita
D000328:Adult; D044466:Asian People / Q000235:genetics; D001483:Base Sequence; D002712:Chlorides / Q000378:metabolism; D004252:DNA Mutational Analysis; D005260:Female; D053579:Gitelman Syndrome / Q000175:diagnosis / Q000235:genetics* / Q000503:physiopathology; D006579:Heterozygote; D006801:Humans; D007008:Hypokalemia / Q000235:genetics / Q000503:physiopathology; D007564:Japan; D008297:Male; D009035:Mothers; D018908:Muscle Weakness / Q000235:genetics / Q000503:physiopathology; D011955:Receptors, Drug / Q000235:genetics; D064486:Solute Carrier Family 12, Member 3; D027981:Symporters / Q000235:genetics; D014237:Trichlormethiazide / Q000008:administration & dosage
D002712:Chlorides; D011955:Receptors, Drug; C578874:SLC12A3 protein, human; D064486:Solute Carrier Family 12, Member 3; D027981:Symporters; D014237:Trichlormethiazide