Activating mutations of the calcium-sensing receptor: The calcilytics ATF-936 and AXT-914 attenuate mutants causing autosomal dominant hypocalcemia and Bartter syndrome type 5

Introduction: Activating mutations of the calcium sensing receptor (CaSR) cause autosomal dominant hypocalcemia (ADH) characterized by low serum calcium, inappropriately low PTH and relative hypercalciuria. Four activating CaSR mutations cause additional renal wasting of sodium, potassium and other salts, a condition called Bartter syndrome type 5. Until today there is no medical treatment for Bartter Syndrome and ADH. We therefore investigated the effects of two novel calcilytics on activating CaSR mutants.