What Is Congenital Adrenal Hyperplasia (CAH)?

Classic CAH

Classic CAH, a more serious and less common form of CAH, is often diagnosed at birth or in early infancy. Classic CAH is caused by a deficiency of 21-hydroxylase, which the body needs to make the hormones cortisol and aldosterone (which helps the body retain sodium). Without enough of these hormones, the adrenal glands start producing more of the male sex hormone androgens, including testosterone, which leads to hormonal imbalances.

There are two subtypes of classic CAH:

• Salt-wasting CAH is the most common, more serious form of classic CAH. It occurs when the body makes too little aldosterone. This causes excessive sodium loss through urine, leading to dehydration and low blood pressure — and potentially life-threatening complications in untreated infants.
• Simple-virilizing CAH is a less common and more mild form of classic CAH. It occurs when the body makes too much androgen and too little cortisol, which can disrupt typical sexual development in both boys and girls. Aldosterone is usually unaffected, though, so this form of CAH does not lead to significant sodium loss or related complications.

Nonclassic CAH

Nonclassic CAH is almost always caused by a partial (mild) deficiency of 21-hydroxylase, which doesn’t affect cortisol or aldosterone, but does lead to excess androgens. Symptoms usually appear before adulthood and include acne, early signs of puberty, and facial hair.

Signs and symptoms depend on CAH type. Sometimes, symptoms are more severe and appear within days after birth. Other times, the symptoms are so mild that CAH may not be diagnosed until later in life.

Classic CAH

• Ambiguous genitalia (in girls)
• Benign testicular adrenal rest tumors
• Deep voice
• Difficulty getting pregnant (in women) and infertility (in men)
  
• Early facial hair (in boys)
• Early signs of puberty
• Enlarged penis
• Excess body or facial hair (in girls)
• Inability to menstruate or irregular menstrual cycles (in women)
• Rapid growth in childhood and early teenage years, but still possibly shorter than both parents
• Virilization (the development of male characteristics in a girl)

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• Arrhythmia (heart rhythm problems)
• Dehydration
  
• Diarrhea
• Low blood pressure
  
• Low glucose levels
  
• Low sodium levels
  
• Metabolic acidosis (too much acid in the blood)
• Poor feeding
• Shock or adrenal crisis (a life-threatening emergency that occurs when cortisol levels are too low to carry out essential bodily functions)
• Vomiting
• Weight loss
  

Even after infancy, children with salt-wasting CAH can be at risk for adrenal crisis if they’re injured, sick, or under physical stress.

Nonclassic CAH

The symptoms of nonclassic CAH, caused by an increase in androgen production, usually appear in childhood, adolescence, or early adulthood. They typically affect sexual development. Some people have such mild symptoms that they never realize they have nonclassic CAH.

• Acne
• Early signs of puberty
• Enlarged penis
• Excess body or facial hair (in girls)
• Fertility problems (in women)
• Irregular menstrual cycles (in women)
• Male-pattern baldness (hair loss near the temples)
• Rapid growth in childhood and early teenage years, but still possibly shorter than both parents
• Small testicles

CAH is caused by a genetic mutation that results in a lack of 21-hydroxylase. This enzyme helps the adrenal glands — located in the upper abdomen — make essential hormones, such as aldosterone and cortisol. When the body is deficient in this enzyme, hormone production is disrupted, and androgen levels can become abnormally high.

If both parents have CAH, their children will definitely inherit the condition.

• Amniocentesis involves inserting a needle into the womb through the abdomen and withdrawing a small amount of fluid from the amniotic sac surrounding the fetus. The fluid is then tested to see if the fetus has a gene abornmality that causes CAH. The test is usually done between weeks 15 and 20 of pregnancy.
• Chorionic villus sampling also involves inserting a needle into the womb, through the abdomen or cervix. A small piece of tissue is extracted from the chorionic villi, a membrane that will later form the placenta. The sample is then tested for the gene that causes CAH. The test is usually done between weeks 10 and 12 of pregnancy.

If CAH is detected in utero, you can work with a genetic counselor, maternal-fetal medicine specialist, and pediatric endocrinologist to get additional testing and come up with a plan to address your baby’s needs.

• Blood and urine tests (to measure hormone levels)
• Genetic testing
• Physical exam
• X-ray (to measure the growth of bones during childhood)
  

Medication Options

• Mineralocorticoids (fludrocortisone) to replace aldosterone, which helps counter sodium loss, prevent adrenal crises, and boost growth and development in children
• Glucocorticoids (dexamethasone, hydrocortisone, prednisolone, prednisone) to replace cortisol, which helps manage adrenal insufficiency, control androgens, and manage growth and development in childhood
  
• Salt supplements (sodium chloride) to help retain salt in the body

People with CAH may need to take more glucocorticoids during stressful times, such as when sick, injured, or getting surgery. These are called “stress doses” and are given to reduce the risk of adrenal crisis. Occasionally, people with nonclassic CAH may also need stress doses, for childbirth, major surgery, or trauma.

Some women with nonclassic CAH may also be given other treatments, including:

• Corticosteroids, to help with fertility or decrease the risk of miscarriage
• Oral contraceptives, to help regulate periods and treat acne and facial hair
• spironolactone (Aldactone), to help treat acne and facial hair
  

Surgery

Parents of girls born with ambiguous genitalia may opt for surgery, especially if the genitals interfere with the ability to urinate. There’s not always a “best” time to have this procedure: Some parents schedule the surgery during the first 2 to 6 months of their child’s life. But many are encouraged to delay the decision about surgery and/or observation until the child is older and can be involved in the decision.

When CAH is detected early, most people with the condition can lead a healthy life. People with classic CAH need to take medication every day — for life — to manage symptoms. People with nonclassic CAH may or may not need medication, depending on the severity of symptoms.

Some people who have CAH may be shorter than their peers. For some, the condition can also affect fertility, but most women with CAH should be able to conceive. Treatment, ongoing monitoring, and psychological support can help with managing the symptoms and allow for a full life.

If you have classic CAH, one of the most serious complications is adrenal crisis — an emergency resulting from dangerously low cortisol levels that needs to be treated right away. In infants, adrenal crises can occur within the first few days of life. But they can also happen in times of stress, such as during an illness or after an injury.

Classic CAH is estimated to affect 1 in 15,000 to 20,000 people at birth in Western countries. About 75 percent of the people who were diagnosed with the condition in infancy have salt-wasting CAH. The other 25 percent have simple virilizing CAH.

Nonclassic CAH affects about 1 in 1,000 people but can occur as frequently as 1 in 100 people in certain ethnic groups.

Support groups and resources available to people with CAH and their caregivers include:

Cares Foundation

This organization is dedicated to advocating for and supporting people with CAH, as well as their parents and caregivers, via Zoom or telephone. They also have in-person meetings and Facebook groups.

National Adrenal Diseases Foundation

The NADF informs and supports people with various adrenal diseases, including CAH, by offering education for patients, caregivers, and providers. The organization recently launched a podcast, “All Things Adrenal,” to spread awareness, education, and real stories from people living with CAH

The Magic Foundation

This nonprofit organization aims to reduce the emotional and physical impact of growth-related endocrine disorders, including CAH, in people of all ages. It provides awareness about the importance of growth monitoring and connects people to expert resources and support groups.

• Congenital adrenal hyperplasia (CAH) is a genetic disorder that causes an imbalance of certain hormones — primarily, too much androgen and too little cortisol.
• There are two types of CAH: classic (which can cause adrenal crisis) and nonclassic (which can disrupt sexual development).
• With the right treatment, most people with CAH can live a healthy life.