[Familial hypocalciuric hypercalcemia].

BACKGROUND

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

METHODS

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.

CONCLUSIONS

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