Nonclassical 21 hydroxylase deficiency may present at any age with a variety of hyperandrogenic symptoms. This form of CAH results from a mild deficiency of the 21-hydroxylase enzyme and is diagnosed by serum elevations of 17 OHP that plot on the nomogram between range for unaffected individuals and levels observed for classical CAH patients (Figure 2).

Similar to classical CAH, nonclassical 21 hydroxylase deficiency may cause premature development of pubic hair, advanced bone age and accelerated linear growth velocity in both males and females. Severe cystic acne has also been attributed to nonclassical CAH. (36, 37)

Women may present with symptoms of androgen excess, including hirsutism, temporal baldness, and infertility. Menarche in females may be normal or delayed, and secondary amenorrhea is a frequent occurrence. Polycystic ovarian syndrome may be seen in these patients. It is likely that excessive levels of adrenal sex steroids disrupt gonadotropin release and with direct effects on the ovary, ultimately lead to the formation of ovarian cysts, which may continue autonomously to produce androgens.

In males, early beard growth, acne, and growth spurt may prompt the diagnosis of nonclassical CAH. A reliable indication of an adrenal, as opposed to testicular, source of androgens is the proportionate small size of the testes compared to the phallus that results from suppression of the hypothalamic pituitary gonadal axis. Symptoms of nonclassical CAH in adult males may be limited to short stature or oligozoospermia and diminished fertility.