["Essential hypernatremia" as a result of on increased osmoreceptor threshold in a boy with Pierre-Robin disease and corpus callosum agenesis].

Hypernatremia was found as a cause of recurrent fever episodes in a 18 month old boy with Mb, Pierre-Robin and agenesia of the corpus callosum. We found values of serum-sodium until 160 mVal/l. Examinations of the osmotic regulation showed a so called "essential hypernatremia" without polyuria and polydipsi. Therefore must be responsible a defect of the osmotic center and thirst center in the hypothalamic area. As therapy a diet of 1000 ml = 1000 kcal = 100 mg Sodium/d. was successful.