Congenital Adrenal Hyperplasia: Diagnosis, Evaluation, and Management

Abstract

1. Zoltan Antal, MD* 2. Ping Zhou, MD† 1. *Fellow 2. †Assistant Professor, Division of Pediatric Endocrinology, Department of Pediatrics, Albert Einstein College of Medicine, Bronx, NY After completing this article, readers should be able to: 1. Describe the pathophysiology of congenital adrenal hyperplasia (CAH). 2. Characterize the signs and symptoms of CAH. 3. Describe the appropriate laboratory evaluation of CAH. 4. Know that CAH can be diagnosed prenatally. 5. Recognize adrenal insufficiency by laboratory and clinical evaluation. 6. Anticipate and plan treatment for both acute adrenal crisis and long-term therapy for a patient who has CAH. 7. Discuss the value of newborn screening for salt-losing CAH in male infants. Congenital adrenal hyperplasia (CAH) refers to a family of inherited disorders of adrenal steroidogenesis. The common functional defect in each disorder is impaired cortisol secretion, resulting in hypersecretion of corticotropin-releasing hormone (CRH) and adrenocorticotropic hormone (ACTH) and consequent hyperplasia of the adrenal glands. More than 90% of cases of CAH are caused by a defect in the enzyme 21-hydroxylase (21-hydroxylase deficiency [21OHD]). Four other enzyme deficiencies in the steroid biosynthesis pathway, along with one cholesterol transport protein defect, account for the remaining cases. Depending on the severity of the enzyme deficiency, 21OHD is defined as classic (severe form) or nonclassic (mild form). Approximately 75% of patients who have the classic form also have salt wasting due to inadequate aldosterone production, further subdividing the classification into classic simple virilizing and classic salt-wasting forms. This review highlights the diagnosis and treatment of 21OHD, with a brief discussion of the other forms of CAH. A Hispanic baby girl is born at term, has a birthweight of 3.1 kg, and has ambiguous genitalia (Fig. 1). During the first week after birth, the baby is clinically stable but demands frequent feeding. On the sixth postnatal day, serum electrolyte measurements are normal. Additional evaluation reveals female internal organs on pelvic ultrasonography and female karyotype. Newborn screening results show 17-hydroxyprogesterone (17-OHP) values of 180 and 679 ng/mL 2 and 5 days …