If the enzyme block impairs androgen synthesis, it is an undervirilizing form, causing inadequate virilization of an affected male fetus. An affected infant may present with ambiguity of the external genitalia, thereby providing few initial diagnostic clues, because an undervirilized male and an overvirilized female infant cannot be distinguished on physical examination. The rise in and ratio of the various precursors is diagnostic of each enzyme defect. In partial enzyme deficiencies, the aldosterone deficiency is not expressed, and patients remain normonatremic and normokalemic. Prenatal diagnosis and treatment are available.
Infants often require supplemental oral salt.
Close monitoring during therapy is critical. Overtreatment with glucocorticoid results in iatrogenic Cushing's disease, which manifests in childhood as obesity, subnormal growth, and bone age delay. Undertreatment with glucocorticoid results in failure to suppress ACTH with consequent hyperandrogenism, manifesting in childhood as virilization and supranormal growth velocity, and eventually as premature termination of growth and ultimate short stature. Compliance with the treatment must be ensured, growth closely monitored, and bone age readings obtained yearly. Affected female infants may require surgical reconstruction with reduction clitoroplasty and construction of a vaginal opening.