Congenital adrenal hyperplasia

Definition

Congenital adrenal hyperplasia refers to a group of inherited adrenal gland disorders. People with this condition do no produce enough of the hormones cortisol and aldosterone, and produce too much of androgen.

Alternative Names

Causes

Congenital adrenal hyperplasia can affect both boys and girls. People with congenital adrenal hyperplasia lack of 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 hormones. This causes early (or inappropriate) appearance of male characteristics.

Newborn girls with this disorder have a swollen clitoris with the urethral opening at the base (ambiguous genitalia, often appearing more male than female). The internal structures of the female reproductive tract (ovaries, uterus, and fallopian tubes) are normal. As the female grows older, some features start to appear male, such as deepening of the voice, facial hair, and failure to menstruate at puberty.

No obvious problems are seen in newborn males, but changes can be seen long before puberty normally occurs. The child becomes increasingly muscular, the penis enlarges, pubic hair appears, and the voice deepens. Boys may appear to enter puberty as early as 2-3 years of age. At puberty, the testes are small.

Some forms of congenital adrenal hyperplasia are more severe and cause adrenal crisis in the newborn due to salt wasting. In this salt-losing form of congenital adrenal hyperplasia, newborns develop severe symptoms shortly after birth, including vomiting, dehydration, electrolyte changes, and cardiac arrhythmias. Untreated, this condition can lead to death within 1 to 6 weeks after birth.

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

Symptoms

• In girls:
  • Ambiguous genitalia
  • Early appearance of pubic and armpit hair
  • Excessive hair growth
  • Deep voice
  • Abnormal menstrual periods
  • Failure to menstruate
• In boys:
  • Early development of masculine characteristics
  • Well-developed musculature
  • Enlarged penis
  • Small testes
  • Early appearance of pubic and armpit hair

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

Exams and Tests

• Low levels of  aldosterone and cortisol
• High levels of urinary 17-ketosteroids
• Normal or low urinary 17-hydroxycorticosteroids
• High levels of 17-OH progesterone
• High levels of serum DHEA sulfate
• X-ray for bone age (demonstrates markedly older bones than what is normal for the person's actual age)
• Abnormal salt levels in blood (serum electrolytes) and urine
• Genetic tests can help diagnose or confirm the disease, and can be useful in the management of the condition.

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

• Pregnanediol
• Estriol - urine
• Estriol - serum

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. Additional doses of medicine are needed during times of stress, such as severe illness or surgery.

The gender of a baby with ambiguous genitalia is determined by examination of the chromosomes (karyotyping). Reconstructive surgery for girls with masculine external genitalia is usually performed between the ages of 1 and 3 months to correct the abnormal appearance.

Parents of children with congenital adrenal hyperplasia should be aware of the side effects of steroid therapy. They should report signs of infection and stress to their health care provider because increases in medication may be required. In addition, steroid medications cannot be stopped suddenly, or adrenal insufficiency will result.

Support Groups

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

Outlook (Prognosis)

The outcome is usually associated with good health, but short stature may result even with treatment. Males have normal fertility. Females may have a smaller opening of the vagina and lower fertility.

Medication to treat this disorder must be continued for life.

Possible Complications

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

When to Contact a Medical Professional

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

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

Prevention

Genetic counseling is indicated for parents with a family history of congenital adrenal hyperplasia (of any type) or a family with a child who has the condition.

Prenatal diagnosis is available for some forms of congenital adrenal hyperplasia. Diagnosis is made in the first trimester by chorionic villus sampling and in the second trimester 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 and can be done on heelstick blood (as part of the routine screenings done on newborns). This test is not yet widely available.