A detailed family history for the occurrence of hypercalcemia, pHPT, MEN1, MEN2, HPT‐JT, FIHP, and FHH should be obtained as the presence of these disorders in a relative will help to guide decisions for appropriate germline mutational analysis of the MEN1, RET, CDC73, or CASR genes, with the results of the tests further guiding clinical management and treatments (Figure 1). This evidence concerns the gene CASR and familial isolated hyperparathyroidism.