Congenital Adrenal Hyperplasia
Overview
Congenital Adrenal Hyperplasia
Congenital adrenal hyperplasia (CAH) is a life-threatening genetic disorder that was once considered a rare disease with severe complications. 21-hydroxylase deficiency is the most common cause of CAH. CAH affects the adrenal glands. Researchers have discovered that mild CAH is common, though it frequently eludes diagnosis. Because it often eludes diagnosis, researchers say it affects one in every 100 to 1000 people in the USA.
The adrenal glands are a pair of walnut-sized organs sitting on top of the kidneys that produce vital hormones, including:
Cortisol
which regulates the body’s response to illness or stress
Androgens
such as testosterone which are male sex hormones
Mineralocorticoids
such as aldosterone, which regulates sodium and potassium levels
When someone has CAH, their body cannot naturally make at least one of the enzymes listed above. There is no cure, but with proper diagnosis and treatment, most people with CAH can lead regular lives.
There are two major types of CAH
Classic CAH
This, the rarer form, is typically detected during infancy. About two-thirds of those with classic CAH have what is known as the salt-losing form. The remaining third have what is known as the simple-virilizing form.
Non-classic CAH
This is the more common form of CAH, and it is milder than classic CAH. Sometimes non-classic CAH can be identified in infancy, but it may not become evident until later in childhood or adulthood.
Those at risk for developing CAH have two parents who have CAH or have two parents who are carriers of CAH. This type of genetic disorder is known as the autosomal recessive inheritance pattern.
Those most at risk of CAH are certain ethnic groups that include:
- Ashkenazi Jews
- Hispanics
- Italians
- Yugoslavs
- Yupik Innuits
Symptoms
Congenital Adrenal Hyperplasia Symptoms
CAH affects different genes in different people. The symptoms vary depending on which gene is involved, the amount of enzyme deficiency, and the type of CAH, classic CAH vs. non-classic CAH.
Both classic and non-classic CAH can cause fertility problems in males and females.
Classic CAH
Male infants who have classic CAH have normal-appearing genitals. However, female infants who have classic CAH may have “ambiguous genitalia.” The clitoris may be enlarged, or the genitals may look similar to those of a male. Infants with classic CAH may be severely affected by a lack of aldosterone, cortisol, or both, whether male or female.
Children with the simple-virilizing and the salt-losing forms of classic CAH may produce an insufficient amount of cortisol. These children may be more vulnerable to stress because healthy blood pressure, blood sugar, and energy levels are harder to maintain.
Other signs of classic CAH in children and adults include:
- Short height in boys and girls
- Appearance of pubic hair at a very early age
- Early puberty in boys and girls
- Rapid growth during childhood, but shorter than average height at maturity
Low cortisol levels may cause an adrenal crisis in those with classic CAH. An adrenal crisis is a life-threatening emergency that can cause symptoms that may include:
- Shock
- Diarrhea
- Vomiting
- Dehydration
- Low blood sugar levels
Non-classic CAH
There are often no symptoms of non-classic CAH when a baby is born, making it more challenging to diagnose in infants. Routine infant blood screenings do not identify the condition, and it usually does not become evident until late childhood or early adulthood. With non-classic CAH, cortisol is frequently the only hormone that is deficient.
The genitals of adult and teenage females with non-classic CAH may appear normal at birth, but later in life, these individuals may have:
- Facial hair
- Severe acne
- A deepening voice
- Excessive body hair
- Early appearance of pubic hair
- Irregular or absent menstrual periods
In males and females alike, indications of non-classic CAH may also include:
- Rapid growth during childhood
- A shorter predicted final height
- An advanced bone age measurement
Diagnosis
Congenital Adrenal Hyperplasia Diagnosis
CAH may be diagnosed before a baby is born, during childhood, or later in life.
Prenatal Testing
Three tests are available to diagnose CAH in an unborn child (fetus), including:
- Chorionic villus sampling, which involves taking cells from the placenta.
- In Amniocentesis, a needle is used to withdraw a sample of amniotic fluid from the womb.
- A maternal blood test will determine if the fetus has CAH and the sex of the fetus.
Newborns and Infants
Physicians in the United States agree that all newborns should be screened for genetic 21-hydroxylase deficiency during the first few days of life to identify the classic form of CAH. However, this screening does not recognize the non-classic form of CAH.
Children and Young Adults
A diagnosis in older children and young adults starts with an examination and a review of symptoms. The doctor will order tests if CAH is suspected. Possible tests include:
- Blood and urine tests, which look for abnormal levels of hormones produced by the adrenal glands.
- Gene testing may be recommended in older children and young adults to diagnose CAH.
Ambiguous Genitalia in Female Infants
Female infants who have CAH may have ambiguous genitalia. The presence of ambiguous genitalia can make it challenging to identify if the child is genetically male or female. Testing is available to analyze chromosomes to identify genetic sex. A pelvic ultrasound can determine female reproductive structures such as the uterus and ovaries.
Contact your pediatrician right away if your infant or child is demonstrating signs of CAH.
Treatments
Congenital Adrenal Hyperplasia Treatments
The information below applies to adults. Contact your pediatrician right away If your infant or child is demonstrating signs of CAH.
Medications
Scientists designed medications for CAH to replace deficient hormones and reduce excess androgen production.
Patients can manage classic CAH by taking hormone replacement medications daily throughout their life. Those who have non-classic CAH may not require any treatment or need only small doses of corticosteroids. During periods of illness or significant stress, such as surgery, additional medications or higher doses may be required.
Medications may include:
Corticosteroids
which replace cortisol
Salt supplements
which help retain salt
Mineralocorticoids
replace aldosterone and are used to help the body retain salt and eliminate excess potassium
The doctor will regularly monitor the effectiveness of medications through physical examinations, and monitor growth and development. These exams include checking the blood pressure, height, weight, and bone growth. The doctor will monitor the patient for side effects, such as impaired growth and loss of bone mass. Monitoring the patient is especially important if steroid-type medication doses are high and used long term. Regular blood tests are required to ensure hormone levels are balanced.
Specialists
