Bartter’s syndrome (antenatal Bartter syndrome, hyperprostaglandin E syndrome) is an autosomal-recessive electrolyte disorder, producing hypokalemia, metabolic alkalosis, hyper-reninism, and hyperaldosteronisms.
- It has now been recognized to be caused by mutations in at least three transport proteins responsible for NaCl absorption in the loop of Henle. Besides mutations in the Na+/K+/2Cl-cotransporter, Bartter’s syndrome can also be caused by mutations in the K+ channel that is present in the apical membrane of the ascending limb (ROMK or KIR1.1).
- This K channel is a K-recycling pathway and its operation is a prerequisite for NaCl absorption through NKCC2.
- Clinically, Bartter syndromes types I and II are indistinguishable. In contrast, a milder form of Bartter’s syndrome is caused by mutations in the basolateral chloride channel (ClC-Kb), an exit pathway for cellular Cl.