A Study to Determine the Effects of NPSP795 on the Calcium-sensing Receptor in Subjects With Autosomal Dominant Hypocalcemia as Measured by PTH Levels and Blood Calcium Concentrations

This is an open-label study looking at the effects of NPSP795 (a selective calcium receptor antagonist) on activating mutations of the Calcium-sensing receptor in patients with Autosomal Dominant Hypocalcemia. Patients with ADH have low blood calcium levels and an inappropriately increased renal calcium excretion, decreased renal phosphate excretion, and hyperphosphatemia. PTH and blood calcium levels will be tested during and after the IV infusion of NPSP795. Concentrations of NPSP795 and length of time of IV infusion will vary depending on measured levels of ionized calcium.