Congenital adrenal hyperplasia

Synonyms

3

Overview

Congenital adrenal hyperplasia (CAH) refers to any of several autosomal recessive diseases resulting from mutations of genes for enzymes mediating the biochemical steps of production of cortisol from cholesterol by the adrenal glands (steroidogenesis). Most of these conditions involve excessive or deficient production of sex steroids and can alter development of primary or secondary sex characteristics in some affected infants, children, or adults. Only a small minority of people with CAH can be said to have an intersex condition, but this attracted American public attention in the late 1990s and many accounts of varying accuracy have appeared in the popular media.

Symptoms

The symptoms of CAH vary depending upon the form of CAH and the sex of the patient. Symptoms can include:

Due to inadequate mineralocorticoids:

• vomiting due to salt-wasting leading to dehydration and death

Due to excess androgens:

• Functional and average sized penis in cases involving extreme virilization (but no sperm)
• Ambiguous genitalia, in some females, such that it can be initially difficult to identify external genitalia as "male" or "female".
• Early pubic hair and rapid growth in childhood
• Precocious puberty or failure of puberty to occur (sexual infantilism: absent or delayed puberty)
• Excessive facial hair, virilization, and/or menstrual irregularity in adolescence
• Infertility due to anovulation
• Enlarged clitoris and shallow vagina

Causes

Congenital adrenal hyperplasia can affect both boys and girls. People with congenital adrenal hyperplasia lack an enzyme needed by the adrenal gland to make the hormones cortisol and aldosterone. Without these hormones, the body produces more androgen, a type of male sex hormone. This causes male characteristics to appear early (or inappropriately).

Prevention

Parents with a family history of congenital adrenal hyperplasia (of any type) or a child who has the condition should consider genetic counseling. Prenatal diagnosis is available for some forms of congenital adrenal hyperplasia. Diagnosis is made in the first trimester by chorionic villus sampling. Diagnosis in the second trimester is made by measuring hormones such as 17-hydroxyprogesterone in the amniotic fluid. A newborn screening test is available for the most common form of congenital adrenal hyperplasia. It can be done on heelstick blood (as part of the routine screenings done on newborns). This test is currently performed in many states. Ask your doctor if it is done in your state.

Diagnosis

Tests to diagnose congenital adrenal hyperplasia include:

Physical exam:

Your child's doctor will examine your child and evaluate symptoms. If, based on these findings, the doctor suspects congenital adrenal hyperplasia, the next step is to confirm the diagnosis with blood and urine tests.
Blood and urine tests:

Tests used to diagnose congenital adrenal hyperplasia measure levels of hormones manufactured by the adrenal glands — cortisol, aldosterone and androgens. A diagnosis can be made when there are abnormal levels of these hormones.

Doctors are required to conduct hormonal tests for congenital adrenal hyperplasia in newborns during the first few days of life. Blood is drawn with a heel prick of the newborn and analyzed.

Prognosis

CAH can be controlled and successfully treated in most patients as long as they remain on drug therapy.

Treatment

The goal of treatment is to return hormone levels to normal. This is done by taking a form of cortisol (dexamethasone, fludrocortisone, or hydrocortisone) every day. People may need additional doses of medicine during times of stress, such as severe illness or surgery. The health care provider will determine the gender of a baby with ambiguous genitalia by checking the chromosomes (karyotyping). Girls with male-looking genitals will usually have surgery between ages 1 month - 3 months to correct the abnormal appearance. Parents of children with congenital adrenal hyperplasia should be aware of the side effects of steroid therapy. Report signs of infection and stress to your health care provider because the child may need more medication. Steroid medications cannot be stopped suddenly, because it may lead to adrenal insufficiency.