Is heterozygosity for the steroid 21-hydroxylase deficiency responsible for hirsutism, premature pubarche, early puberty, and precocious puberty in children?

We applied the ACTH-stimulation test developed in our laboratory for the detection of heterozygous carriers of the 21-hydroxylase deficiency gene to patients suffering from hirsutism (n = 89), premature pubarche (n = 75), early puberty (n = 37), and precocious puberty (n = 22). While, in the general population, this test is positive in less than 2%, we found in 33% of hirsute patients, in 41% of patients with premature pubarche, and in 33% of patients with early puberty a hormonal response similar to the one seen in heterozygous carriers for the 21-hydroxylase defect. In contrast, only 18% of patients with precocious puberty responded abnormally. Thus we speculate that, at least in some patients with hirsutism, premature pubarche, and early puberty, heterozygosity for the 21-hydroxylase defect plays a major role in the pathogenesis of these disorders.