Study of the genetic and extragenetic determinants of alpha-ketosteroid production in man.

The present investigation was undertaken to evaluate the influence of heredity on steroid hormone production of man. The steroid patterns of adult male, dichorionic monozygotic triplets were examined in appropriate periods before, during and after adrenal stimulation with adrenocorticotropic hormone (ACTH). The results of this investigation provide evidence for the existence of a significant genetic determinant of the level of steroid hormone production and metabolism, as well as an important extra-genetic influence that can modify this factor. The nature of this extragenetic influence is suggested from previous studies of physiological differences in twins.