[Panhypopituitarism in one of 2 monozygotic twins]

Anterior panhypopituitarism has been observed in one of monozygous twin girls. Etiologic investigations were negative and only suggested an hypothetic perinatal insult. Genetic abnormalities could be excluded. Replacement therapy with human growth hormone was strikingly successful, with a remarkable catch-up growth and, however, a velocity of bone age comparable with the velocity of growth.