Familial nephrogenic diabetes insipidus: report of two families.

Familial nephrogenic diabetes insipidus is a hereditary disorder, generally transmitted by sex-linked recessive genes with varying degrees of penetrance in females. The onset of this disorder occurs in infancy, usually characterized by unexplained fever, recurrent dehydration and failure to thrive. If left unrecognized, recurrent hyperosmolality and hypernatremia will lead to retarded growth and neurologic sequelae. Intracranial hemorrhage, consciousness disturbance and even mortality may occur in cases of acute dehydration episodes. We report on two families with nephrogenic diabetes insipidus, whose various symptoms and signs were studied to establish an accurate diagnosis. In pediatric practices, it is very important to recognize early those infants with obscure symptoms in order to preserve their psychomotor development and growth potential.