Atypical Presentation of Familial Hypocalciuric Hypercalcemia: Case Report

Abstract Background: Differentiation between familial hypocalciuric hypercalcemia (FHH) and primary hyperparathyroidism (PHPT) can be challenging in certain cases in the absence of DNA analysis of the calcium sensing receptor gene. The distinction between those two clinical entities with overlapping biochemical features therefore relies on the calcium to creatinine clearance ratio (CCCR), which is expected to be low in FHH (<0.01 in 80% of cases and between 0.01 and 0.02 in approximately 20% of patients)1. Patients with PHPT usually have a CCCR of>= …