Congenital adrenal hyperplasia

Definition

Congenital adrenal hyperplasia refers to a group of inherited disorders of the adrenal gland.

Alternative Names

Adrenogenital syndrome; 21-hydroxylase deficiency

Causes, incidence, and risk factors

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).

About 1 in 10,000 to 18,000 children are born with congenital adrenal hyperplasia.

Symptoms

Girls will usually have normal internal female reproductive organs (ovaries, uterus, and fallopian tubes). They may have the following external changes:

• Abnormal menstrual periods
• Genitals that look both male and female (ambiguous genitalia), often appearing more male than female
• Deep voice
• Early appearance of pubic and armpit hair
• Excessive hair growth and facial hair
• Failure to menstruate

Boys won't have any obvious problems at birth. However, they may appear to enter puberty as early as 2 - 3 years of age. Changes may include:

• Deep voice
• Early appearance of pubic and armpit hair
• Early development of masculine characteristics
• Enlarged penis
• Small testes
• Well-developed muscles

Both boys and girls will be tall as children but significantly shorter than normal as adults.

Some forms of congenital adrenal hyperplasia are more severe and cause adrenal crisis in the newborn due to loss of salt. In this form of congenital adrenal hyperplasia, newborns develop severe symptoms shortly after birth, including:

• Cardiac arrhythmias
• Dehydration
• Electrolyte changes
• Vomiting

Signs and tests

• Abnormal salt levels in blood (serum electrolytes) and urine
• High levels of 17-OH progesterone
• High levels of serum DHEA sulfate
• High levels of urinary 17-ketosteroids
• Low levels of aldosterone and cortisol
• Normal or low urinary 17-hydroxycorticosteroids
• X-ray for bone age (shows older bones than normal for the person's age)

Genetic tests can help diagnose, confirm, and manage the disease.

This disease may also affect the results of the following tests:

• Estriol - serum
• Estriol - urine
• Pregnanediol

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.

Support Groups

• National Adrenal Diseases Foundation: www.medhelp.org/nadf/
• The MAGIC Foundation: www.magicfoundation.org
• The CARES Foundation: www.caresfoundation.org

Expectations (prognosis)

People with this condition usually have good health. However, they may be shorter than normal, even with treatment.

Males have normal fertility. Females may have a smaller opening of the vagina and lower fertility.

People with this disorder must take medication their entire lives.

Untreated, adrenal crisis can lead to death within 1 - 6 weeks after birth.

Complications

• Abnormal female external genitals (internal organs are normal)
• Adrenal crisis, including hyponatremia and shock (especially in newborns)
• Early development of male sexual characteristics
• High blood pressure
• Low blood sugar
• Short height as an adult, despite early, rapid childhood growth
• Side effects of steroid medications used as treatment
• Tumors of the testes in adult men

Calling your health care provider

Call for an appointment with your health care provider if your child develops symptoms of this disorder.

If you had a child with this disorder or you have a family history of this disease and you plan to have other children, talk to your health care provider before conceiving. Genetic counseling is important if you have a family history of congenital adrenal hyperplasia.

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.

References

White PC. Congenital adrenal hyperplasia and related disorders. In: Kliegman RM, Behrman RE, Jenson HB, Stanton BF. Nelson Textbook of Pediatrics. 18th ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 577.