Additional genes to be considered for screening in phenocopies include CDC73 (also known as HRPT2) which is a tumor suppressor gene that encodes the protein parafibromin (mutations implicated in hyperparathyroid-jaw tumor syndrome), CaSR which encodes the calcium sensing receptor (mutations associated with familial benign hypocalciuric hypercalcemias), GNA11 that encodes the G-protein alpha 11, and AP2S1 which encodes the adaptor-related protein complex 2, sigma 1 subunit, particularly in patients with familial hyperparathyroidism. The gene discussed is CASR; the disease is familial hypocalciuric hypercalcemia.