[Diagnostic steps and management of a rare cause of hypercalcemia]

Background: Distinguishing familial hypocalciuric hypercalcemia (FHH) a rare cause of usually mild, parathyroid hormone-dependent hypercalcemia from other causes is central for management due to its benign and usually mild course. Case: Diagnostic approach to a mild hypercalcemia in a 36-years-old female with FHH. Conclusion: This case highlights the importance of a precise and stepwise diagnostic approach to identify rare causes of hypercalcemia like FHH, an autosomal-dominant inherited, pathogenic variant of the calcium sensing receptor.