Classic congenital adrenal hyperplasia (CAH) is a serious inherited genetic disorder that affects your adrenal glands. You’re usually diagnosed with it when you’re born or shortly after. You’ll need lifelong treatment, but ongoing medical care can help you live a healthy life. Here’s what you need to know.
What happens when you have classic congenital adrenal hyperplasia?
Your adrenal glands sit on top of your kidneys. With classic CAH, these glands don’t make enough of key hormones that help your body function, including one or more of the following:
Cortisol. Regulates blood pressure, blood sugar, and other functions that use energy when you’re stressed, sick, or hurt
Aldosterone. Helps balance your sodium and fluid levels, along with blood pressure
A lack of cortisol triggers the release of adrenocorticotropic hormone (ACTH). Your body then shifts the ACTH stimulation of the adrenals into an androgen hormone-producing pathway. Both male and female children need these hormones to grow and develop. But kids with classic CAH have very higher levels of androgens – often labeled as male or “masculinizing” sex hormones – than what’s considered normal.
What are the types of classic congenital adrenal hyperplasia?
Around 1 in every 10,000 to 18,000 people worldwide are born with classic CAH. There are two main forms:
Salt-wasting CAH. Around 3 out of 4 babies born with classic CAH have this form. You pee out too much sodium and water because you don’t make enough aldosterone.
Simple-virilizing CAH. Around 1 in 4 babies are simple virilizers. This means you make excess androgens due to low cortisol, but your aldosterone production is usually fine. For that reason, simple-virilizing CAH is less serious than salt-wasting CAH.
Classic congenital adrenal hyperplasia and nonclassic congenital adrenal hyperplasia are the two most common kinds of congenital adrenal hyperplasia, making up 95% of all cases. Classic CAH is serious and sometimes fatal. Nonclassic CAH is a milder form, and you may not know you have it until you’re an older child, teenager, or adult.
What causes classic congenital adrenal hyperplasia?
The most common cause of CAH is a defect in the gene that makes the 21-hydroxylase enzyme. But some people have CAH due to an 11-hydroxylase enzyme deficiency. These enzymes are proteins responsible for triggering chemical reactions in the adrenal glands, including the kind that make hormones.
Classic CAH is an autosomal recessive genetic disorder. That means that for a child to inherit it, both parents must pass on a specific mutation, or gene change, of the enzyme that causes adrenal gland dysfunction.
You won’t have symptoms if you’re born with one abnormal gene. But “silent carriers” can still pass the mutation to their children.
What are risk factors for classic congenital adrenal hyperplasia?
Risk factors for classic CAH include:
- Both parents have CAH.
- Both parents have a gene mutation that causes CAH.
While people of all races and ethnicities can get CAH, you’re more likely to have genes that cause it if your family ancestry is:
- Ashkenazi Jewish
- Latino
- Mediterranean
- Yugoslav
- Yup’ik
What are symptoms of classic congenital adrenal hyperplasia?
If it goes undiagnosed or untreated, serious signs and symptoms of salt-wasting CAH typically show up within a few days or weeks of birth. These include:
- Dehydration
- Low sodium levels
- Low blood sugar
- Too much acid in the blood
- Heart rhythm problems
- Throwing up
- Diarrhea
- Weight loss
Salt-wasting can lead to adrenal crisis. This is a medical emergency that causes a dangerous drop in blood pressure. Call 911 or get to the hospital right way if it happens to your child. They can go into shock (when not enough blood and oxygen get to your brain and organs) and die without fast treatment.
Symptoms of adrenal crisis may include:
- Confusion
- Crankiness
- Fast heart rate
- Seizure
- Coma
Salt-wasting and adrenal crisis from CAH are less likely to happen while on treatment. But they can still happen in certain situations, including if your child:
- Gets sick
- Puts their body under a lot of physical stress
- Has a fever or infection
- Has surgery
- Forgets or stops taking their medication
Ask your child’s doctor about how you can help lessen the chances of an adrenal crisis.
How does classic congenital adrenal hyperplasia affect males and females?
Too many androgens might cause your child’s genitals or body to look different from those of other kids their age. The extent of those changes depends on your child’s specific sex organs.
Genetic females at birth generally have typical internal sex organs, including a uterus, ovaries, and fallopian tubes. But they may have external changes at birth and later in life, including:
- Enlarged clitoris or fused labia that look more like a penis
- Typical male traits like larger muscles, a deeper voice, and excess facial hair
- Irregular or absent menstrual periods
- Trouble getting pregnant
Genetic males at birth may not always have clear signs of classic CAH, but some symptoms may include the following:
- Enlarged penis or darker scrotum
- Noncancerous tumors on the testicles
- Facial hair at an early age
In some cases, a baby assigned male at birth might actually be a genetic female with a severe degree of external masculinization.
Both male and female children with excess androgens may show early signs of puberty. If they don't get treatment early on, they may:
- Grow fast
- Be shorter than normal when they stop growing
- Get bad acne or pubic/armpit hair at a young age
Treatment for classic congenital adrenal hyperplasia
In the U.S., health providers routinely screen newborns for classic CAH. Typically, a doctor or nurse will prick your baby’s heel to collect a few drops of blood for the lab test between 2 and 4 days after birth.
People with classic CAH need ongoing treatment, which usually includes medications and emotional support. In some cases, surgery may be needed. The main goal of treatment is to foster healthy growth and development, like what would happen if your child’s adrenal glands worked well.
Depending on your child’s symptoms, you may need a mix of health professionals, including:
Urologist. A doctor who treats urinary tract conditions
Mental health professional. A specialist such as a counselor or psychologist
Pediatric endocrinologist. A doctor who treats childhood hormonal issues
Reproductive endocrinologist. A specialist in female reproductive conditions
Geneticist. A health expert in genes and genetic disorders
The main treatment for classic CAH is daily steroid replacement for life, but you may need one or more of the following medications:
- Corticosteroids such as hydrocortisone or prednisone to replace cortisol and control excess androgens.
- Mineralocorticoids like fludrocortisone to replace aldosterone
- Salt supplements to keep salt and fluids in your body
- Hormonal birth control to regulate absent or irregular menstrual cycles
- Anti-androgen drugs to lower excess androgen levels
A new medication, crinecerfont (Crenessity), was recently approved by the FDA for people ages 4 and older. It may help curb the amount of corticosteroid needed by lowering androgen levels. Your child’s doctor will decide the best treatment based on blood tests, symptoms, and physical exams. Medication changes may be needed in certain stressful situations, like if your child gets sick or needs to have surgery.
Your doctor can go over the pros and cons of surgery to address problems that affect your child’s genitals, including if they have trouble peeing or your child wants to change how their external sex organs look.
Questions to ask your doctor
To learn more, here are some questions to ask your doctor about how to manage life with classic congenital adrenal hyperplasia:
- What specific type of CAH does my child have?
- What are all the treatment options?
- How often do we need to come in for check-ups?
- Do people with CAH need treatment forever?
- Is classic CAH curable?
- Are there physical activities my child can’t do?
- Do we need to change treatment if my child gets sick?
- What if my child needs surgery?
Other questions you may want to ask include:
- What are the long-term effects of classic CAH?
- What are the signs of an emergency?
- What should I do if my child has an adrenal crisis?
- Can people with classic CAH have kids?
- What other specialists should someone with CAH see?
- Can you recommend support groups for me or my child?
- Will my child need to see a different kind of doctor when they’re an adult?
Talk to your doctor about genetic counseling if you or your partner has congenital adrenal hyperplasia or a family history of the condition and plan to have children. If you’re pregnant, consider prenatal testing to detect CAH before your child is born.
Find more information about classic congenital adrenal hyperplasia through groups like the CARES Foundation, MAGIC Foundation, and National Adrenal Diseases Foundation. Your doctor can connect you with local classic CAH support groups and resources.
Show Sources
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SOURCES:
FDA: "FDA Approves New Treatment for Congenital Adrenal Hyperplasia."
National Organization for Rare Disorders (NORD): “Congenital Adrenal Hyperplasia.”
Nature Reviews Endocrinology: “Management challenges and therapeutic advances in congenital adrenal hyperplasia.”
Johns Hopkins Medicine: “Congenital Adrenal Hyperplasia.”
CARES Foundation: “What is CAH?”
Eunice Kennedy Shriver National Institute of Child Health and Human Development: “About Congenital Adrenal Hyperplasia,” “What are the symptoms of congenital adrenal hyperplasia (CAH)?”
The Leo Fung Center for CAH and Disorders of Sex Development: “Congenital Adrenal Hyperplasia in the Newborn.”
Hassenfeld Children’s Hospital at NYU Langone: “Types of Congenital Adrenal Hyperplasia,” “Diagnosing Congenital Adrenal Hyperplasia.”
Ann & Robert H. Lurie Children’s Hospital of Chicago: “Congenital Adrenal Hyperplasia.”
Cleveland Clinic: “Congenital Adrenal Hyperplasia.”
Mayo Clinic: “Congenital adrenal hyperplasia.”
BMC Medical Ethics: “A principled ethical approach to intersex paediatric surgeries.”
The Magic Foundation: “About Magic Foundation.”
National Adrenal Diseases Foundation: “Congenital Adrenal Hyperplasia (CAH).”
