Fig. (4) Hereditary Disorders of the Distal Convoluted Tubule (DCT). Gitelman syndrome is caused by a mutated electroneutral sodiumchloride transporter. The decreased NaCl absorption impairs magnesium absorption through the TRPM6 channel. WNK4 inhibits the NaCl transporter and decreases NaCl absorption. A mutated WNK4 in Gordon syndrome leads to increased NaCl absorption in the DCT. WNK1 inhibits WNK4. A mutated WKN1 inhibits more strongly increasing NaCl absorption in Gordon syndrome.