McCune-Albright Syndrome: Causes, Symptoms, and Treatment
Medically reviewed by Harsha Moole, MD, Internal Medicine. Last reviewed: October 23, 2026.
What kind of doctor treats McCune-Albright Syndrome?
An endocrinologist, a doctor who treats gland and hormone problems, and an orthopedist, a doctor who treats bone and joint diseases, are often part of the care team. A direct primary care or concierge doctor can be a first stop for an evaluation and can refer you to a specialist when needed.
What is McCune-Albright syndrome?
McCune-Albright syndrome is a disorder that affects the bones, skin, and several hormone-producing (endocrine) tissues. It is very rare. It occurs in 1 in 100,000 to 1 in 1,000,000 people worldwide.
In the bones, abnormal scar-like tissue replaces healthy bone. This is called fibrous dysplasia. The weaker tissue makes bones more likely to break. The abnormal areas may occur in many bones, often on one side of the body.
Symptoms
Symptoms differ from person to person. Common signs include:
- Bone pain and broken bones. A broken bone may be the first sign.
- Bones that grow unevenly or change shape. Uneven leg growth may cause limping, and the spine may curve (scoliosis).
- Light brown skin patches with irregular borders. They may be seen at birth and often appear on only one side of the body.
- Early puberty. Girls may reach puberty early and often have menstrual bleeding by age 2.
- Thyroid problems. The thyroid is a butterfly-shaped gland at the base of the neck. It may swell or make too much thyroid hormone, causing a fast heart rate, weight loss, tremors, and sweating.
- Too much growth hormone, which can cause large hands and feet.
- Vision or hearing loss, if bone growths press on nearby nerves.
Rarely, too much cortisol, a hormone that helps manage stress, causes Cushing syndrome.
Causes and who gets it
McCune-Albright syndrome is caused by a mutation, or change, in the GNAS gene. The change happens at random very early in development. It is not inherited.
Some of the body's cells have the changed gene and others do not. How severe the condition is depends on the number and location of cells with the change. The condition is not passed to the next generation.
How doctors diagnose it
Doctors may suspect it at birth because of the skin patches. For many people, it is not suspected until late infancy or childhood, when early puberty starts or bone changes become obvious.
A diagnosis is based on the exam, a detailed history, X-rays, and blood tests. Doctors look over the whole body for skin patches. Blood tests may show high hormone levels. Bone scans show how much of the skeleton is affected.
A bone biopsy, which means taking a small sample of bone to study under a microscope, may be needed if other tests are unclear. Rarely, genetic testing is needed if the diagnosis is uncertain.
Treatment
There is no cure. Treatment is directed at the symptoms each person has. The FDA has not approved a medicine to treat fibrous dysplasia, but doctors may use a therapy approved for a related condition. Care may need a team of specialists, such as pediatricians, orthopedists, endocrinologists, and dermatologists.
For the bones, options may include:
- Monitoring, if there are no symptoms and no risk of a break.
- Physical therapy and exercises that strengthen the muscles around bone growths, which may help lower the risk of a break.
- A cast, splint, or brace for broken bones.
- Surgery to prevent and repair broken bones, treat scoliosis, and fix misshapen bone.
- Medicines called bisphosphonates have been used for bone pain. Doctors first rule out other causes of pain and try other pain options.
Hormone problems are treated with medicines that help stop a gland from making too much hormone or block what the hormone does. Girls with mild early puberty may not need treatment, but they need close checkups. People with bone growths near the eyes and ears need regular hearing and vision exams.
When to see a doctor
See a doctor if a young child shows signs of puberty, such as menstrual periods or early breast development. A broken bone or bone pain may be the first sign of this condition.
Tell your doctor about any change in vision or hearing. Bone growths near the eyes and ears can press on nerves and cause vision loss or hearing problems.
Some babies have a rare but serious problem from too much cortisol. Signs include poor growth, high blood pressure, a red face, and extra body hair. See a doctor promptly if a baby has these signs.
Call 911 or go to the emergency room for a head or spine injury, bleeding that will not stop, sudden severe pain, fainting, or trouble breathing.
How a direct primary care or concierge doctor fits in
A direct primary care doctor charges a flat monthly fee instead of billing insurance, while a concierge doctor usually charges more and often works alongside insurance. Either type of doctor can talk through your options, help coordinate the many specialists involved, and follow your progress over time.
Common questions
Is McCune-Albright syndrome inherited?
No, it is not inherited. It is caused by a random change in the GNAS gene that happens very early in development, and it is not passed to the next generation.
Can McCune-Albright syndrome be cured?
No, there is no cure. Treatment is directed at the specific symptoms each person has, and it may need a team of specialists.
Is McCune-Albright syndrome cancer?
No, the bone growths are not cancer. In very rare cases, fewer than 1 percent, they can turn into a bone cancer called osteosarcoma.
Why does it cause early puberty?
It causes early puberty because the glands that release sex hormones are overly active.
Sources
- MedlinePlus Genetics - McCune-Albright syndrome
- National Institute of Arthritis and Musculoskeletal and Skin Diseases - Fibrous Dysplasia: Diagnosis, Treatment, and Steps to Take
- National Organization for Rare Disorders - Fibrous Dysplasia / McCune-Albright Syndrome
Medical Disclaimer
This content is for general educational and informational purposes only and is not medical advice. It is not a substitute for professional medical advice, diagnosis, or treatment, and reading it does not create a doctor-patient relationship. Always seek the advice of your physician or another qualified health provider with any questions about a medical condition, and never disregard or delay seeking professional advice because of something you read here. If you think you may have a medical emergency, call 911 (or your local emergency number) immediately.
