Figure 4.Nomogram relating baseline to ACTH-stimulated serum concentrations of 17-hydroxyprogesterone (17-OHP). The scales are logarithmic. A regression line for all data points is shown. Data points cluster as shown into three nonoverlapping groups: classic and non-classic forms of 21-hydroxylase deficiency are readily distinguished from each other and from those that are heterozygotes and unaffected. Distinguishing unaffected from heterozygotes is difficult.107 Adapted from: New MI, Lorenzen F, Lerner AJ, et al. 1983 Genotyping steroid 21-hydroxylase deficiency: hormonal reference data. J Clin Endocrinol Metab 57:320-6. Permission obtained.