Congenital Adrenal Hyperplasia

Definition

Congenital adrenal hyperplasia is the name given to a group of inherited disorders of the adrenal gland.

Alternative Names

Adrenogenital syndrome; 21-hydroxylase deficiency; CAH

Causes

People have 2 adrenal glands. One is located on top of each of their kidneys. These glands make hormones, such as cortisol and aldosterone, that are essential for life. People with congenital adrenal hyperplasia lack an enzyme the adrenal glands need to make the hormones.

At the same time, the body produces more androgen, a type of male sex hormone. This causes male characteristics to appear early (or inappropriately).

Congenital adrenal hyperplasia can affect both boys and girls. About 1 in 10,000 to 18,000 children are born with congenital adrenal hyperplasia.

Symptoms

Symptoms will vary, depending on the type of congenital adrenal hyperplasia someone has, and their age when the disorder is diagnosed.

• Children with milder forms may not have signs or symptoms of congenital adrenal hyperplasia and may not be diagnosed until as late as adolescence.
• Girls with a more severe form often have masculinized genitals at birth and may be diagnosed before symptoms appear.
• Boys will appear normal at birth, even if they have a more severe form.

In children with the more severe form of the disorder, symptoms often develop within 2 or 3 weeks after birth.

• Poor feeding or vomiting
• Dehydration
• Electrolyte changes (abnormal levels of sodium and potassium in the blood)
• Abnormal heart rhythm

Girls with the milder form will usually have normal female reproductive organs (ovaries, uterus, and fallopian tubes). They may also have the following changes:

• Abnormal menstrual periods or failure to menstruate
• Early appearance of pubic or armpit hair
• Excessive hair growth or facial hair
• Some enlargement of the clitoris

Boys with the milder form often appear normal at birth. However, they may appear to enter puberty early. Symptoms may include:

• Deepening voice
• Early appearance of pubic or armpit hair
• Enlarged penis but normal testes
• Well-developed muscles

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

Exams and Tests

Your child's health care provider will order certain tests. Common blood tests include:

• Serum electrolytes
• Aldosterone
• Renin
• Cortisol

X-ray of the left hand and wrist may show that the child's bones appear to be those of someone older than their actual age.

Genetic tests can help diagnose or confirm the disorder, but they are rarely needed.

Treatment

The goal of treatment is to return hormone levels to normal, or near normal. This is done by taking a form of cortisol, most often hydrocortisone. People may need additional doses of medicine during times of stress, such as severe illness or surgery.

The provider will determine the genetic sex of the baby with abnormal genitalia by checking the chromosomes (karyotyping). 

Steroids used to treat congenital adrenal hyperplasia do not usually cause side effects such as obesity or weak bones, because the doses replace the hormones that the child's body cannot make. It is important for parents to report signs of infection and stress to their child's provider because the child may need more medicine. Steroids cannot be stopped suddenly because doing so may lead to adrenal insufficiency.

Support Groups

These organizations may be helpful:

• National Adrenal Diseases Foundation -- www.nadf.us
• The MAGIC Foundation -- www.magicfoundation.org
• The CARES Foundation -- caresfoundation.org

Outlook (Prognosis)

People with this disorder must take medicine their entire life. They most often have good health. However, they may be shorter than normal adults, even with treatment.

In some cases, congenital adrenal hyperplasia can affect fertility.

Possible Complications

Complications may include:

• High blood pressure
• Low blood sugar
• Low sodium

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 heel stick blood (as part of the routine screenings done on newborns). This test is currently performed in most states.