[Idiopathic hypercalcaemia. The effect of hypercalcaemia on renal function (author's transl)].

A case of idiopathic hypercalcaemia diagnosed in a six months old infant is reported. Nephrologic symptoms were conspicuous: decreased clearance, increased serum creatinin and urea nitrogen level, restricted ability of concentration, damage of the renal acidification; slight nephrocalcinosis was shown histologically. The serum calcium level and calcium excretion became normal under the treatment with hydrochlorothiazide and prednisolon. The function of the kidney and the general status of the infant significantly improved.