Familial hypocalciuric hypercalcemia (FHH) is characterized by lifelong elevations of serum calcium concentrations in association with normal or mildly raised serum parathyroid hormone (PTH) concentrations in 80% of patients and low urinary calcium excretion (urinary calcium‐to‐creatinine clearance ratio <0.01) in 80% of patients.1, 2 FHH may be inherited as an autosomal dominant condition, and it is a genetically heterogeneous disorder with three recognized variants, FHH1‐3. This evidence concerns the gene PTH and familial hypocalciuric hypercalcemia.