Lack of this essential step in the formation of all biologically active steroids affects both the adrenal cortex and the ovary and is also inherited in autosomal recessive fashion. Thus, there is decreased synthesis of glucocorticoids, mineralocorticoids, androgens, and estrogens. These infants are severely ill at birth and rarely survive. The external genitalia ambiguity results from the massive increase in DHA that is androgenic when available in excess, and also can be utilized to form any more potent androgens in peripheral tissues. Thus, females may be slightly virilized and males incompletely masculinized with a variable degree of hypospadias. As in 21-hydroxylase deficiency, milder nonclassic cases may be common with mild hirsutism and elevated DHA (and DHAS) being the only distinguishing features. The spectrum of clinical phenotypes also includes both salt wasting and non-salt wasting forms. The degree of the enzyme defect cannot be extrapolated from the degree of external genitalia ambiguity.