What Is Congenital Adrenal Hyperplasia (CAH)?

Congenital Adrenal Hyperplasia, also known as CAH, is a collection of genetic conditions passed down through families that affect your adrenal glands. This condition impacts the production of three vital hormones: cortisol, aldosterone, and androgens. Specifically, insufficient cortisol and aldosterone production and overproduction of androgens. Congenital Adrenal Hyperplasia is broadly classified into two types: Classic CAH and Non-Classic CAH, each with different impacts and severities. Non-Classic CAH is more common than Classic CAH.

Signs & Symptoms

Congenital Adrenal Hyperplasia symptoms can vary depending on the type of CAH and can impact both infants and adults.

CAH symptoms:

• Salt-wasting crises—This symptom, resulting from insufficient aldosterone, leads to a dangerous loss of salt in the body. It can cause dehydration, low blood pressure, and shock.
• Rapid growth in childhood and early puberty—Overproduction of androgens can result in children growing quickly and reaching puberty earlier than usual, resulting in premature bone maturation and potentially reduced adult height.
• Ambiguous genitalia in female newborns—Excess androgens can cause female newborns to have atypical genital development, often making it more difficult to determine the child's biological gender at birth.
• Infertility—Both men and women with CAH can experience fertility issues, which may be linked to hormone imbalances and other physical complications of the disorder.
• Fatigue or weakness—These symptoms can arise from insufficient cortisol, which is critical for energy production and stress response.
• Low blood sugar—Inadequate cortisol can also disrupt glucose regulation, potentially causing hypoglycemia.
• High blood pressure—This can result from an imbalance in your body's salt and water.

Causes

CAH is mainly caused by genetic mutations that are passed down from parents to their children. These mutations affect an enzyme called 21-hydroxylase, which is critical for the adrenal glands to produce cortisol and aldosterone effectively. When this enzyme is deficient or absent due to these mutations, it disrupts hormone production, triggering the signs and symptoms of CAH.

Risk Factors

The risk factors for Congenital Adrenal Hyperplasia are exclusively genetic. A child is at a higher risk of inheriting this condition if both parents are carriers of the mutated gene that causes CAH. Individuals of certain ancestries, such as Latino, Mediterranean, and Yup'ik heritage have been found to have a higher incidence of CAH.

Diagnosis

The diagnosis of Congenital Adrenal Hyperplasia involves a series of tests designed to assess hormone levels and identify any relevant genetic mutations.

Diagnostic tests include:

• Newborn screening—Many doctors conduct a routine newborn screening for CAH, which involves testing a small blood sample for indicators of CAH.
• Hormone testing—Blood and urine tests can be conducted to measure levels of hormones produced by the adrenal glands. Abnormal levels may indicate CAH.
• Genetic testing—This test identifies any gene mutations known to cause CAH.
• Imaging tests—In some cases, imaging tests like ultrasound may be used to examine the adrenal glands or reproductive organs, providing further information about the condition's impact on your body.

These tests, along with a thorough review of symptoms and family history, help healthcare professionals make an accurate diagnosis and plan an appropriate course of treatment.

Complications

While Congenital Adrenal Hyperplasia is a manageable condition, if left untreated or not adequately managed, it can lead to several complications.

These complications can vary based on the type of CAH:

• Classic CAH—This severe form of the condition can lead to life-threatening adrenal crises due to severe salt loss, necessitating immediate medical attention. Additionally, women with classic CAH may experience issues such as irregular periods and excessive body hair, due to elevated androgen levels.
• Non-Classic CAH—This milder form of CAH can result in an early start of puberty, where a child begins developing sexually at a younger age than usual. You may experience rapid growth during childhood, but your adult height may be shorter than average. Other complications can include irregular periods, acne, and fertility issues in both men and women.

Treatment

While Congenital Adrenal Hyperplasia is not curable, it can be effectively managed with appropriate treatment. Congenital Adrenal Hyperplasia treatments may include hormone replacement, supplements, and surgery. Hormone replacement therapy is typically used to restore the balance of cortisol and aldosterone in the body, and salt supplements may be recommended to counter salt loss. In certain circumstances, such as atypical genital development, surgery might be considered as part of the treatment plan. Regular medical follow-up is crucial to adjust treatment as needed and ensure the best possible quality of life.

Prevention

There is currently no known way to prevent Congenital Adrenal Hyperplasia. This condition is inherited and cannot be cured. However, with early diagnosis and appropriate lifelong management, people with CAH can lead healthy, fulfilling lives. If you or your partner are carriers of the CAH gene mutation or have a family history of CAH, genetic counseling could be beneficial to better understand the potential risks and to make informed decisions about family planning.