WHAT IS CONGENITAL ADRENAL HYPERPLASIA?
Congenital - Present at birth.
Adrenal - Involving the adrenal glands.
Hyperplasia - A condition in which there is an increase in the number of normal cells in a tissue or organ.
Congenital Adrenal Hyperplasia (CAH) is an inherited condition that is present at birth. In CAH the adrenal glands do not produce enough of the right amount of hormones that are needed for our bodies to function normally. The adrenal glands are a pair of small organs, each about the size of a walnut. They are located on top of each of the kidneys just below the ribs in the back. They produce three hormones, or chemical messengers called cortisol (hydrocortisone), aldosterone (salt- retaining hormone), and androgens (male sex hormones).
CAH occurs when the adrenal glands do not produce enough cortisol and aldosterone hormones, and instead produce too much of the male-like hormones, androgens.
The overproduction of male-like hormones can affect a baby before it is born. Girls with CAH may have an enlarged clitoris at birth, and may develop masculine features as they grow, such as deepening of the voice, facial hair, and failure to menstruate or abnormal periods at puberty. Girls with severe CAH may be mistaken for boys at birth. Boys with CAH are born with normal genitals, but may soon become muscular, develop pubic hair, an enlarged penis and a deepening of the voice sometimes as early as two to three years of age. The testicles of boys with untreated CAH cannot function well and may not make sperm normally.
Children’s growth also may be affected. Their long bones have growth plates at the ends. These plates allow for growth and eventually “close” when normal adult height is reached. High levels of androgens may cause rapid early growth. However, if these high levels of male-like hormones continue, the growth plates may “close-up” too early resulting in a very short adult.
In its most severe form, called salt-wasting CAH, a life-threatening adrenal crisis can occur if the disorder is not treated quickly. An adrenal crisis can cause dehydration, shock, and death within 14 days of birth. Other forms include Simple Virilizing CAH and milder forms.
HOW DO CHILDREN GET CONGENITAL ADRENAL HYPERPLASIA?
CAH is a genetic disorder which means it is inherited from the parents. It is a recessive disease, which means that a child must inherit one copy of the defective gene from each parent. Each parent carries a defective gene. When two carriers have children, each pregnancy carries a 25% risk of producing a baby with CAH.
HOW DO I FIND OUT IF MY BABY HAS CAH?
CAH is diagnosed by a careful examination of the genitals of babies when they are born and by blood and urine tests which measure the hormones made by the adrenal glands.
All babies in Texas are required by law to be screened by a heel-prick blood test for certain disorders including CAH. The first screen is done within the first 48 hours of life and a second test is done at one to two weeks of age.
For more detailed information about CAH, please visit the Texas Department of State Health Services Newborn Screening website at http://www.dshs.state.tx.us/newborn/cah.shtm.
HOW IS CAH TREATED?
Children with CAH should be examined regularly by a pediatric endocrinologist. CAH is treated by hormone replacement. Two types of hormone replacement medications are given to correct the abnormal hormone levels in CAH. Both boys and girls with CAH need to take a cortisol-like medication to control the excessive male-like hormone production. These hormones are given two or three times each day by mouth as a pill. Children with salt-wasting CAH may in addition receive a salt-retaining hormone pill once or twice daily with or without salt tablets or salt added to the baby formula to prevent severe dehydration.
Girls born with CAH who have masculine external genitals will need surgery to reconstruct the clitoris and/or labia. This is usually performed between the ages of one and three.
CAH is never “outgrown” so children with CAH must take hormone replacement medication for their whole life. The pediatric endocrinologist will check height, weight, blood pressure, and order x-ray of the wrist as needed to look at the bone age, as well as blood tests to measure hormone levels. The amount of medication will be different for each child and will need to be changed as the child grows or if sick or injured.