[Familial hypocalciuric hypercalcemia]

Familial hypocalciuric hypercalcemia is often considered but rarely proved during evaluation for hypercalcemia. The disorder is characterized by lifelong persisting hypercalcemia and hypocalciuria.

In this study, the authors analyzed a 25-yr-old Hungarian woman with mild hypercalcemia detected by routine laboratory testing. Evaluation revealed hypercalcemia, relative hypocalciuria and non-suppressed serum intact parathormone level. The diagnosis of hypocalciuric hypercalcemia was confirmed by the low ratio of calcium clearance/creatinine clearance. Genetic studies for calcium-sensing receptor gene mutations were performed in blood DNA samples. After polymerase chain reaction amplification, DNA sequencing of exons 2-7 were performed. The proband and her father had the same mutation (CCG-->CTG) at codon 55 of exon 2, leading to a conversion of the proline to a leucine.

This case report presents the first case of familial hypocalciuric hypercalcemia, published in a Hungarian patient.