Congenital adrenal hyperplasia (CAH)

What is congenital adrenal hyperplasia (CAH)?

Congenital adrenal hyperplasia (CAH) affects the adrenal glands, which are located above each kidney.

These glands make important hormones, including:

• Cortisol - Regulates blood pressure, blood sugar and how the body responds to illness and stress

• Aldosterone - Helps the body maintain a healthy balance of salt and water

• Androgens (such as testosterone) - Impact growth and development in boys and girls

Risk factors

CAH has many types, and each causes different problems with these three hormones. CAH can cause girls to have genitals that make them appear more like boys. Sometimes, it causes children to enter puberty sooner than they should. In severe cases, CAH can cause serious illness.

What are the different types of congenital adrenal hyperplasia (CAH)?

The two major types of CAH are:

Classic CAH

This is the rarest and most severe type of CAH. People with classic CAH aren’t able to produce any cortisol. They need medication throughout their life to help their body perform necessary functions that cortisol would normally control. These functions include regulating blood pressure and blood sugar and responding to illness. These children also have very high androgen levels, which causes problems with early puberty, growth and development. Some children with more severe cases of classic CAH aren’t able to produce aldosterone. This is called salt-wasting because these children can’t maintain salt levels.

Non-classic CAH 

This is the most common type of CAH. The symptoms are mild, and some children with nonclassic CAH won’t need any medication. These children typically produce enough cortisol and aldosterone for healthy function, but they may produce excess androgens. Too many androgens can cause early puberty and impact reproductive function.

What are the signs and symptoms of congenital adrenal hyperplasia (CAH)?

Classic CAH

Doctors typically diagnose classic CAH when your child is an infant.

Doctors and parents may notice these symptoms:

• Ambiguous genitalia in newborn girls

• Dehydration

• Low blood pressure

• Low sodium and high potassium levels

• Poor feeding

• Vomiting

• Weight loss

Children with classic CAH may also develop other symptoms as they grow and develop, such as:

• Deeper voices than normal

• Severe acne

• Early or excess hair on their faces or armpits or pubic area

• Short adult height

• Fertility problems

Non-classic CAH

Children with nonclassic CAH may not have symptoms until later in childhood, teenage years or early adulthood. Some people with nonclassic CAH never have symptoms. If and when they experience symptoms, it’s typically mild.

These symptoms include:

• Acne

• Early signs of puberty

• Rapid growth, but to a final height less than expected for their family

• Excess facial or body hair in girls

• Irregular menstruation in girls

• Enlarged penis in boys

• Fertility problems in adulthood

How is congenital adrenal hyperplasia (CAH)?

Doctors may find CAH in a prenatal ultrasound, but it often goes undetected until birth or soon after.

Tests that we use to confirm a diagnosis of CAH include:

• Prenatal tests - If you are pregnant and already have a child with CAH, then you have a 25% chance of having another child with CAH with each pregnancy. Your doctor may recommend prenatal testing, which can identify some types of CAH before your baby is born.

• Newborn screening - Doctors usually detect classic CAH during routine newborn screening. Doctors prick your baby’s heel at birth and collect a few drops of blood to screen for many conditions. Experts at Children’s Health work with the Texas newborn screening system to analyze test results and provide follow-up care if your baby tests positive for classic CAH. Our team coordinates any additional tests your baby might need to confirm a diagnosis and determine the best treatment.

Sometimes, a child is born with signs or symptoms of classic CAH, but they have a negative newborn screening result. In this case, your doctor may request further testing.

Newborn screening usually doesn’t detect nonclassic CAH, and children usually don’t have symptoms until they’re older.

We may use these additional tests to diagnose classic and nonclassic CAH:

• Blood tests - These tests check hormone levels.

• Genetic tests - These tests check for gene problems that cause CAH.

• Imaging - These tests include ultrasounds, X-rays and CT scans. Doctors may use these tests to get images of your child’s urinary tract, bladder, genital organs and adrenal glands that can help confirm a CAH diagnosis. Doctors might also X-ray your child’s hand and wrist to check their bones for common signs of growth problems associated with CAH.

What causes congenital adrenal hyperplasia (CAH)?

CAH is an inherited genetic disorder that occurs when a child inherits a specific problem (mutation) in a gene. This gene mutation prevents the body from creating an enzyme needed to produce proper amounts of cortisol, aldosterone and androgens. About 95% of all CAH cases result from the lack of the 21-hydroxylase enzyme.

For a child to have CAH, both parents must either have CAH or be carriers for the genetic problem that causes the condition.

How is congenital adrenal hyperplasia (CAH) treated?

The Pediatric Congenital Adrenal Hyperplasia Program at Children’s Health is one of the nation’s top centers for all types of CAH. We provide the latest treatments to help children best manage their condition and enjoy full lives.

Classic CAH

• Medication - Your child will need daily medication to ensure that they have the right balance of important hormones in the body. Hydrocortisone may be one of the medications. Doctors will adjust the types of medication and dosage as your child grows and develops to help them best manage their condition.

• Surgery - Some girls are born with ambiguous genitalia, which means that sexual organs on the outside of the body don’t match most girls’ organs. Teenage women may choose to undergo surgery to correct the appearance and function of their genitalia. Our urologists at Children’s Health are world leaders in these complex surgical treatments.

• Mental health support - Living with CAH can be stressful and challenging at times. Our psychologists and social workers can support your child’s and your family’s mental health needs.

• Emergency care - If your child can’t take their medicine by mouth because of vomiting or unconsciousness, you may need to give them an injection of their medication. We will teach you how to do this and ensure you’re prepared for an emergency.

Learn more about hydrocortisone injections.

Non-classic CAH

If your child has nonclassic CAH, they may not need treatment until they experience symptoms. If your child has symptoms, your doctor might provide medication such as hydrocortisone but in lower doses than for children with classic CAH.

Transitioning to adult care - When your child turns 18, we help them easily transition to adult care with the expert CAH team at UT Southwestern Medical Center.