Congenital adrenal hyperplasia (CAH)
What is congenital adrenal hyperplasia?
Congenital adrenal hyperplasia (CAH) is a group of genetic disorders that affect the adrenal glands causing abnormalities of the hormones produced in these glands. CAH can affect both males and females and may lead to abnormal development of the genitals.
What are the adrenal glands?
The adrenal glands are small glands that are located on top of the kidney. The adrenal gland is responsible for producing multiple hormones. The middle of the adrenal gland produces adrenaline and this is not affected by CAH. The outer portion of the adrenal gland makes three hormones that can be affected by CAH:
- Cortisol – the stress hormone
- Aldosterone – helps to keep the amount of salt and water normal in the blood
- Androgen – male hormones that are important for both females and males.
Children with congenital adrenal hyperplasia generally do not produce enough of the body’s stress hormone, cortisol. These children have various problems with the other two types of hormones. If aldosterone is affected, the body may not be able to hold on to enough salt, and if the androgens are affected, the adrenal glands may make too much or too little male hormone leading to genital abnormalities.
What causes CAH?
Congenital adrenal hyperplasia is due to a defect in an enzyme that is needed to make cortisol, or the stress hormone. The same defect may cause a problem with the production of aldosterone, leading to a condition called salt-wasting where the body cannot hold on to enough salt. With these enzyme defects, the adrenal gland may over-produce or under-produce the male hormones, leading to abnormal genitalia in babies. The most common defect is in an enzyme called 21-hydroxylase where children cannot make enough cortisol, make too much male hormone, and may or may not have abnormalities in the aldosterone production.
Symptoms of CAH
The symptoms of CAH vary by age group.
In babies the symptoms include:
- Drowsiness
- Poor feeding
- Pale skin
- Abnormal genitals
- Poor growth
- Abnormal newborn screening
In older children/adults the symptoms include:
- Early puberty
- Tall stature in children
- Menstrual abnormalities in females
- Infertility
Treatment of CAH
CAH is treated by replacing the stress hormone with a steroid that is very similar to cortisol, for example hydrocortisone or prednisone. Treatment with medications that replace the cortisol help to keep the amount of male hormone at a normal level. If needed, the aldosterone is replaced with a medication called fludrocortisone (florinef). The levels of the hormones must be carefully monitored by a pediatric endocrinologist.