Hormonal phenotype and HLA-genotype in families of patients with congenital adrenal hyperplasia (21-hydroxylase deficiency).

The response of 17-hydroxyprogesterone (17-OHP) and cortisol (F) to a 6-hr ACTH stimulation in families of patients with congenital adrenal hyperplasia due to 21-hydroxylase deficiency was studied. These studies demonstrated that siblings who should be heterozygous carriers of the 21-hydroxylase deficiency gene based on HLA genotyping are hormonally different from the general population. In pre- and early pubertal children predicted to be heterozygous carriers of the gene based on HLA genotyping, the 17-OHP level (13.1 +/- 4.5 ng/ml), the rate of increase of 17-OHP (0.03 +/- 0.01), and the ratio of 17-OHP/F at 6 hr (0.27 +/- 0.07) were significantly higher (P less than 0.001) than in the control population, (3.9 +/- 1.9, 0.009 +/- 0.005, and 0.08 +/- 0.04 ng/ml, respectively). In late and postpubertal males, these hormonal parameters in the heterozygotes (17 +/- 9.7, 0.04 +/- 0.026, 0.42 +/- 0.33 ng/ml, respectively) were significantly higher (P less than 0.001) than in the general population (5.3 +/- 1.6, 0.009 +/- 0.004, and 0.1 +/- 0.03 ng/ml, respectively). In postmenarchal females, the mean hormone responses in the heterozygotes (12.1 +/- 9.7, 0.03 +/- 0.02, and 0.27 +/- 0.24 ng/ml, respectively) were significantly higher (P less than 0.005, less than 0.01, less than 0.005, respectively) than in the general population (5.2 +/- 2.5, 0.01 +/- 0.007, and 0.1 +/- 0.04 ng/ml, respectively). However, the overlapping values did not permit a clear differentiation of the hormonal responses in these two groups. Another (ACTH) stimulation in one family demonstrated that a father of a patient probably is a previously unrecognized homozygous affected patient and,thus, revision of the congenital adrenal hyperplasia (CAH) genotype for this family was required.