PTH and familial hypocalciuric hypercalcemia: FHH is characterized biochemically by lifelong modest elevation of the serum calcium concentration with a relatively mismatched hypocalciuria and normal or mildly elevated circulating parathyroid hormone (PTH) level that is not suppressed by the hypercalcemia.1,2 Individuals with FHH are usually asymptomatic, and the disorder is considered benign.