Endocrine Abstracts

Familial hypocalciuric hypercalcemia is an inherited disease caused by inactivating heterozygous mutations in the gene encoding calcium-sensitive receptors, that affects calcium metabolism and generally follows a benign course. It must be also considered in the differential diagnosis of hyperparathyroidism. Six patients presenting to our internal diseases clinic between January, 2010, and June, 2015, were evaluated in terms of clinical and biochemical parameters. The youngest of our patients was 21 and the oldest was 86. Four were women and two were men. The children of five of our cases and the mother of one were assessed in a polyclinic environment. At evaluation, the presence of familial hypocalciuric hypercalcemia was considered on the basis of moderate hypercalcemia, threshold elevated parathormone levels and a significant decrease in daily calcium expulsion in urine. Diagnosis was confirmed in five patients through determination of similar laboratory findings for calcium metabolism in the children,and also in the mother of our young patient, and on the basis of exclusion of other causes of hypercalcemia. Assessment of calcium metabolism following correction of other factors that may be affected will help clinicians avoid misdiagnosis.

Consideration of familial hypocalciuric hypercalcemia in the diagnostic approach to hypercalcemia and at differential diagnosis of primary hyperparathyroidism will prevent unnecessary surgery.