Alexander Disease: Causes, Symptoms, and Treatment
Medically reviewed by Achuta Uppu, MD, Internal Medicine. Last reviewed: October 23, 2026.
What kind of doctor treats Alexander Disease?
A neurologist, a doctor who treats brain and nerve conditions, usually cares for people with Alexander disease. A geneticist, a doctor who treats inherited conditions, can confirm the diagnosis. 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 Alexander disease?
Alexander disease is a rare disorder of the nervous system. It belongs to a group of disorders called leukodystrophies. These involve the destruction of myelin, the fatty covering that insulates nerve fibers and helps nerve signals travel fast. The disease is marked by abnormal protein deposits called Rosenthal fibers. They build up in astroglial cells, which support and nourish other cells in the brain and spinal cord. Alexander disease is progressive, so it tends to get worse over time.
Symptoms
Symptoms depend on when the disease starts. Doctors group it into two main types. Type I usually begins by age 4. Type II can begin at any age, but mostly after age 4.
Type I signs include:
- Failure to grow and gain weight at the expected rate.
- Delays in learning physical, mental, and behavioral skills.
- Seizures, which are sudden bursts of uncontrolled electrical activity in the brain.
- A head that keeps getting larger, called macrocephaly.
- Stiff muscles and restricted movement, called spasticity.
- Poor coordination, called ataxia.
- Vomiting and trouble swallowing, coughing, breathing, or talking.
Nearly 90% of infants with Alexander disease have developmental problems and seizures. People with type II rarely have delays in development, an enlarged head, or seizures. About 50% have trouble with swallowing or talking, about 75% have poor coordination, and about 33% have stiff muscles.
Causes and who gets it
Changes in the GFAP gene cause Alexander disease. The GFAP gene makes a protein called glial fibrillary acidic protein. This protein is found in astrocytes, cells that support other cells in the brain and spinal cord. The changed protein is thought to build up in these cells and form Rosenthal fibers, which impair cell function. About 95% of cases are caused by GFAP changes. The condition follows an autosomal dominant pattern. That means one copy of the changed gene is enough to cause it. Most cases come from a new gene change, so there is no family history. When a parent has the change, each child has a 50% chance of getting it.
How doctors diagnose it
Doctors look at symptoms and use brain scans. MRI, a scan that uses magnets to make pictures of the brain, can show signs of the disease. Being certain of the diagnosis rests on finding a GFAP change in the person's DNA, from a blood sample or a swab inside the cheek. In about 5% of cases no GFAP change is found, so a negative test does not fully rule out the disease.
Treatment
Zanvastro (zilganersen) is the first FDA-approved treatment for Alexander disease. It is an antisense oligonucleotide, a type of medicine that reduces production of the abnormal GFAP protein before it can build up and cause more damage. Doctors give it as an injection into the spinal canal by a trained health professional. In studies, treated patients aged 5 and older who had trouble walking walked faster than those who got no treatment. Children aged 2 to 4 improved on tests of motor skills like standing and running. The most common side effects are vomiting, back pain, cough, headache, and post-lumbar puncture syndrome, which means problems that follow a spinal tap. Aseptic meningitis, swelling of the lining around the brain and spinal cord, has been reported in patients treated with this medicine. Tell your doctor right away if you develop signs of meningitis. Care also includes help for symptoms and genetic counseling for families.
When to see a doctor
Call 911 if you or someone you care for has trouble breathing, fainting, a seizure that lasts more than 5 minutes, a fever with a stiff neck, or is very sleepy or hard to wake. Get care right away if a child loses skills they once had, has more seizures than usual, or has trouble swallowing or coughing. If you take Zanvastro and develop symptoms that might be meningitis, tell your doctor right away.
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. This doctor can watch a child's growth and development and help coordinate care with a neurologist. They can also manage everyday health needs over the long term.
Common questions
Is Alexander disease inherited?
It can be, but most cases come from a new gene change, with no family history. It follows an autosomal dominant pattern, so one changed gene copy is enough to cause it. When a parent has the change, each child has a 50% chance of getting it.
How rare is Alexander disease?
It affects less than 1 in a million people. About 500 cases have been reported since it was first described in 1949.
Is there a treatment for Alexander disease?
Yes. The FDA approved Zanvastro (zilganersen), the first FDA-approved treatment for this disease. It reduces production of the abnormal GFAP protein. Care also includes help for symptoms.
Does it always start in babies?
No. Type I usually begins by age 4, but type II can begin at any age, mostly after age 4. Adult cases are sometimes mistaken for multiple sclerosis.
Sources
- U.S. Food and Drug Administration - FDA Approves First Drug to Treat Alexander Disease
- MedlinePlus Genetics - Alexander disease
- National Organization for Rare Disorders - Alexander Disease
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.
