Néphrocalcinose de l’enfant

Nephrocalcinosis, the diagnosis of which is now made easier by ultrasonography, is not exceptional in children and even infants. Its etiologies are multiple, but almost all of them involve a metabolic disorder, most often of genetic or iatrogenic origin, increasing the urinary excretion of calcium or oxalate. The most frequent causes vary according to age. Nephrocalcinosis in newborn and infants suggests three main causes : “prematurity-associated hypercalciuria”, the origin of which, multifactorial, is mostly iatrogenic, early-onset tubulopathies (distal tubular acidosis, Bartter's syndrome), and infantile-onset primary hyperoxaluria, which is fortunately very rare. In older children, the main causes are : distal tubular acidosis, primary hyperoxaluria, and hypercalciurias from known genetic origin (Dent's disease, familial hypomagnesemia-hypercalciuria) or still “idiopathic”. The prognosis depends upon the extension of calcic deposit and, above all, on the feasibility, by treating the causal disease, of preventing the calcification process.