What is congenital adrenal hyperplasia?
Congenital adrenal hyperplasia, also known as CAH, is a problem in the adrenal glands. Adrenal glands are located at the top of the kidneys.
The adrenal glands make several hormones in the body, such as cortisol, aldosterone and androgens (testosterone-like hormones). With CAH, the body cannot make enough cortisol and aldosterone, and it makes too many androgens.
Cortisol regulates blood pressure, blood sugar and energy, and it helps the body recover from illness. Aldosterone helps keep the body’s salt levels normal. Androgens are hormones that start puberty and are important for normal growth and development in boys and girls. CAH can be a life-threatening problem in babies, so it is important to find out early and to start treatment right away if someone has CAH.
What causes congenital adrenal hyperplasia?
CAH is caused by a mutation (change) in a gene that alters how the adrenal glands make cortisol and aldosterone. Usually, both parents are carriers of the gene mutation, but often do not have CAH themselves because only one out of two versions of their gene carries the mutation, while the other is normal. However, if a child gets an abnormal gene from each parent (resulting in both versions of the gene carrying a mutation), then the child will have CAH.
What are the signs and symptoms of congenital adrenal hyperplasia?
Girls with CAH may be born with atypical sex organs, which is caused by being exposed to adrenal androgen hormones while they are developing inside the womb. Boys have normal-appearing sex organs. Many infants with CAH develop severe illness with vomiting (throwing up) and low blood pressure if they are not diagnosed and treated by 1 to 2 weeks of age.
In older children, if not properly treated, low cortisol levels can lead to feeling tired all the time (fatigue), upset stomach, throwing up, low blood pressure and possibly death. Low aldosterone can lead to low salt levels in the body, dehydration (loss of body water) and possibly death. Too much androgens can cause children to grow too fast and start puberty early. The children then stop growing at an early age and may end up being much shorter than normal adults.
What are some of the long-term problems from congenital adrenal hyperplasia?
Children with CAH need to take medicines their whole life. If they take their medicines as directed, they should live long, healthy lives. Even with good treatment, however, final adult height in children with CAH may be shorter than expected for families. Females with CAH may have difficulty having regular menstrual periods and fertility can be affected in both females and males.
What tests are used to diagnose congenital adrenal hyperplasia?
Blood tests need to be done to diagnose CAH. All 50 states test all newborns for CAH. If a baby has a positive newborn screen for CAH, a blood test is then done to confirm the diagnosis. The blood test measures salt and hormone levels in the body. Genetic testing can also be done on parents and may be helpful in deciding the risk of having another child with CAH.
How is congenital adrenal hyperplasia treated?
There is no cure for CAH, but there is treatment. Treatment of CAH requires several medicines:
- Hydrocortisone, also known as Cortef, is given 2 or 3 times per day.
- Fludrocortisone, also known as Florinef, may be given 1 or 2 times a day.
- Extra salt may be needed in the diet of some children.
When children with CAH are sick with fever, vomiting, diarrhea (loose bowel movements), or a major illness, they need a higher dose of hydrocortisone to keep them from getting very sick. If they are not able to take their hydrocortisone because they cannot wake up or because they are vomiting, they may need a shot of hydrocortisone. If a child is sick and not able to take their hydrocortisone, it is important to seek medical help right away.
In girls with CAH, families may decide to proceed with surgery to have the sex organs appear more like other girls. As children are growing, it is important to get frequent blood tests to check hormone levels and growth to make sure they are getting the right amount of medicine. X-rays of the hand are also done on a regular basis to help monitor growth.