Until 1966 many asymptomatic hypercalcemic patients were identified to have familial hypocalciuric hypercalcemia (FHH), then Jackson and Boonstra described their first patient with hypercalcemia presumed to have hyperparathyroidism. He was not cured despite the removal of three and a half hyperplastic parathyroid glands. Subsequently, seventeen family members with hypercalcemia were identified in three generations.

• In the year 1966 FHH was first described by Jackson and Boonstra in a hypercalcemic patient presumed to have hyperparathyroidism. He was not cured despite the removal of three and a half hyperplastic parathyroid glands. Subsequently, seventeen family members with hypercalcemia were identified in three generations.^{[1]_SpringerLink-2|[2]}

• A similar family was identified in the year 1972 by Foley Et al. The family members of both the families were asymptomatic and hypercalcemic which is very typical of FHH.^{_SpringerLink-2|[2]}

• In 1990 ten cases of pancreatitis were reported in patients with family members of FHH.^[3]

• In 1990 the National Institutes of Health (NIH) held a conference to establish the principles for diagnosing FHH along with its medical and surgical management guidelines.^{_The_Journal_of_Clinical_Endocrinology_&_Metabolism_|_Oxford_Academic-4|[4]}
• In 1993 Brown Et al identified a bovine parathyroid cell calcium-sensing receptor cDNA by expression cloning in Xenopus laevis oocytes. The cDNA encodes a predicted 120-kD polypeptide containing a large extracellular domain and 7 membrane-spanning regions characteristic of G protein-coupled cell surface receptors. In addition to parathyroid tissue, it also identified the presence of CaSR in regions of the kidney involved in calcium-regulated calcium and magnesium reabsorption.^[5]

• In 1995 studies were conducted to characterize the mutations of calcium-sensing receptors in FHH and neonatal hyperparathyroidism.^[6]