The Ca(2+)-sensing receptor (CaSR) regulates Ca(2+) homeostasis in the body by monitoring extracellular levels of Ca(2+) ([Ca(2+)]o) and amino acids. Mutations at the hinge region of the N-terminal Venus flytrap domain (VFTD) produce either receptor inactivation (L173P. P221Q) or activation (L173F. P221L) related to hypercalcemic or hypocalcemic disorders. https://www.roneverhart.com/Annie-Brocoli-Noel-en-spectacle/