Familial hypocalciuric hypercalcemia: review of three cases.

Familial hypocalciuric hypercalcemia, also denominated familial benign hypercalcemia, is an uncommon cause of hypercalcemia. It is caused by mutations of the calcium-sensing receptor, which are inherited in an autosomal dominant high-penetrance fashion. Generally, patients are asymptomatic, and heterozygote cases are diagnosed in childhood or adulthood, when diagnostic work-up of an incidentally discovered hypercalcemia ensues. This disorder is characterized by moderate hypercalcemia, with normal parathormone levels and low urine calcium excretion. It is very important to diagnose this condition, as it does not require surgical procedures, unlike primary hyperparathyroidism, which needs parathyroidectomy in 50% of cases. We present 3 cases of familial hypocalciuric hypercalcemia belonging to the same family, and provide an updated review on the topic.