[Familial nephrogenic diabetes insipidus with chronic hypernatremia and cerebral calcifications].

The authors report on the unusual evolution of two brothers suffering from nephrogenic diabetes insipidus after a 25-year follow-up. The polyuro-polydipsic syndrome was clinically well tolerated, without acute complications even during infancy. However, despite the lack of water restriction and the presence of thirst sensation, the children remained chronically hypernatremic. An intellectual deficiency was present, with a dysmorphic syndrome unrelated to a biochemically determined central nervous system disorder, or an X fragility. Calcifications of basal ganglia and frontal lobes were discovered on a cerebral computed tomography performed at 16 and 18 years. This syndrome may represent a specific entity.