Types of Congenital Adrenal Hyperplasia
Doctors at Hassenfeld Children's Hospital of New York at NYU Langone diagnose and manage congenital adrenal hyperplasia, a group of inherited conditions that affect the adrenal glands. These glands, located on top of the kidneys, produce hormones that are essential for many body functions. In congenital adrenal hyperplasia, a child’s body produces abnormal levels of the hormones cortisol, aldosterone, and androgens, or male sex hormones.
There are two main types of congenital adrenal hyperplasia—classic and nonclassic. The majority of children with either type of the condition don’t produce enough 21-hydroxylase, an enzyme that helps the adrenal glands make cortisol and aldosterone.
Classic Congenital Adrenal Hyperplasia
Classic congenital adrenal hyperplasia, usually diagnosed during infancy, is the more severe of the two types. Children with this condition don’t make enough cortisol, which helps regulate blood sugar and enables the body to respond to stress and illness. The condition also limits production of aldosterone, a hormone that regulates blood pressure by maintaining the body’s salt and water levels. These children also produce excess amounts of male sex hormones called androgens.
Most infants with classic congenital adrenal hyperplasia have what’s known as the salt-wasting form of the condition, which causes them to lose too much water and salt in their urine. These children have very low levels of cortisol and aldosterone, which can lead to a dangerous drop in blood pressure and require immediate treatment. Boys may have an enlarged penis, and girls may have ambiguous or masculine-looking genitals.
Another classic form, called simple virilizing adrenal hyperplasia, causes boys and girls to appear more masculine, but it does not have a dramatic effect on blood pressure. Children with simple virilizing adrenal hyperplasia have decreased levels of cortisol, normal levels of aldosterone, and increased androgens.
Nonclassic Congenital Adrenal Hyperplasia
Nonclassic, or late-onset, congenital adrenal hyperplasia is more common than the classic form. It is usually diagnosed in early adolescence or in younger children who have early signs of puberty. Children with nonclassic congenital adrenal hyperplasia have normal levels of aldosterone and excess amounts of androgens. Symptoms are often far milder than those associated with the classic condition, and many children don’t need treatment. The nonclassic form does not progress to the classic form.
Our doctors use information from a baby’s newborn screening test to identify congenital adrenal hyperplasia. They also perform tests to diagnose the condition and distinguish between the different types.