The classic Bartter syndrome (Bartter syndrome type III) is caused by a mutation in the gene CLCNKB encoding the chloride ion channel ClC-Kb located in the thick segment of the ascending branch of the medullary loop.[13] Patients with Bartter’s syndrome are more likely to experience growth and development delay before the age of 3, with normal blood magnesium levels and normal or high urinary calcium levels. This evidence concerns the gene CLCNKB and Bartter syndrome.