Hypercalcemia due to neonatal severe HPT (NSHPT) secondary to homozygous or heterozygous mutations of CASR, has been treated since 2011 with cinacalcet, in association with biphosphonates, in order to avoid post-surgical hypoparathyroidism (2, 16, 23, 25, 36, 40). This evidence concerns the gene CASR and hypoparathyroidism.