RESUMO
Gitelman syndrome is an autosomal recessive renal tubular disorder characterized by hypokalemic metabolic alkalosis, and it is distinguished from Batter syndrome by hypomagnesemia and hypocalciuria. This disorder is caused by mutation in SLC12A3 gene which encodes thiazide-sensitive Na(+)-Cl(-)cotransporter (NCCT) which is expressed in the apical membrane of cells, lining distal convoluted tubule. A 8-year old boy who presented with Rolandic epilepsy, and horseshoe kidney accidentally showed clinical features of metabolic alkalosis, hypokalemia, hypocalciuria without hypomagnesemia. So we identified a heterozygote mutation and an abnormal splicing in the SLC12A3 gene, encoding NCCT. The mutation was detected in the exon 15 and 22 of SLC12A3 gene.