Bartter syndrome is a rare genetic disorder caused by mutations in genes that encode various components of the renal tubular transport system, such as K+ channel (KCNJ1 gene), Cl– channel (CLCNKA and CLCNKB genes), their cotransporters (SLC12A1 gene), subunits of these channels (BSND gene), or regulators of the expression of certain transport channels (MAGED2 gene). This evidence concerns the gene KCNJ1 and Bartter syndrome.