Familial hypercalcemia and hypercalciuria : no mutations in the Ca2+-sensing receptor gene

A 6-year-old boy presented with persistent hypercalcemia, hypercalciuria and nephrocalcinosis from early infancy. His 40-year-old father also had hypercalcemia and hypercalciuria. In both individuals serum values of intact parathyroid hormone (PTH) were repeatedly normal. Although these findings suggest a functional abnormality of the calcium-sensing receptor (CaR), no mutations in coding regions of the CaR gene could be demonstrated.