Myotonic Dystrophy: Causes, Symptoms, and Treatment
Medically reviewed by Harsha Moole, MD, Internal Medicine. Last reviewed: October 23, 2026.
What kind of doctor treats Myotonic Dystrophy?
A neurologist (a doctor who treats brain, nerve and muscle conditions) usually treats myotonic dystrophy. It is an inherited muscle disease. It causes weakness and muscle loss that get worse over time. It can also affect the eyes, the heart and other body systems. 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 myotonic dystrophy?
Myotonic dystrophy is part of a group of inherited disorders called muscular dystrophies. It is the most common form of muscular dystrophy that begins in adulthood.
People with it often have myotonia. This means muscles stay tight after use and cannot relax. It affects at least 1 in 8,000 people worldwide.
There are two major types, type 1 and type 2. Their signs overlap, but type 2 tends to be milder than type 1.
Type 1 is grouped into mild, classic and congenital forms. Congenital myotonic dystrophy is often apparent at birth. It can cause breathing problems and delayed development, and some of these problems can be life-threatening.
Symptoms
Symptoms often begin in a person's twenties or thirties, but they can occur at any age. The severity varies widely, even among members of the same family.
- In type 1, weakness mostly affects muscles far from the center of the body, such as the lower legs, hands, neck and face.
- In type 2, weakness mostly affects muscles near the center of the body, such as the neck, shoulders, elbows and hips.
- Other signs include cataracts (clouding of the lens of the eye) and problems with the electrical signals that control the heartbeat.
- Some people develop diabetes, in which blood sugar levels can become dangerously high.
Problems with the heart's electrical signals are common. They are a significant cause of early death and are sometimes linked to sudden death.
Sleepiness during the day and sleep apnea (pauses in breathing during sleep) can also occur. Anxiety and depression are often seen.
Causes and who gets it
Type 1 is caused by changes in the DMPK gene. Type 2 is caused by changes in the CNBP gene. A gene is a set of instructions in your cells. In each case, a piece of DNA is repeated too many times, which makes an unstable region in the gene. These changes stop muscle cells and cells in other tissues from working normally.
Both types are inherited in an autosomal dominant pattern. This means one changed copy of the gene is enough to cause the condition. In most cases, an affected person has one parent with the condition.
As the condition passes down, it generally begins earlier and gets more severe. This is called anticipation. The evidence for anticipation appears only in type 1.
How doctors diagnose it
The diagnosis and treatment details below come from sources about type 1.
Doctors suspect type 1 when a person has the typical muscle weakness. Genetic testing of the DMPK gene confirms it. The test finds the gene change in nearly all affected people.
Relatives at risk can have genetic testing too. This allows early treatment of heart problems, diabetes and cataracts.
Treatment
No specific treatment exists for the weakness that keeps getting worse in type 1. Treatments for muscular dystrophies aim to keep people independent as long as possible and prevent complications.
A physiatrist (a rehabilitation doctor) or a therapist can help decide if you need leg braces, a wheelchair or other aids.
Myotonia in type 1 is typically mild to moderate and rarely needs treatment.
See a cardiologist (a heart doctor) for heart symptoms or an abnormal EKG (a test that records the heart's electrical signals). Dangerous heart rhythms can occur before other symptoms. A pacemaker or an implantable cardioverter-defibrillator may prevent life-threatening heart rhythm problems.
Cataracts can be removed if they affect vision. Breathing support from a machine may be needed for lung problems.
Before any surgery, tell the whole medical team, including the anesthesia team, that you have myotonic dystrophy. Careful attention to anesthesia is required.
- In type 1, experts suggest a yearly EKG.
- They also suggest an eye exam every two years.
When to see a doctor
See a cardiologist if you have heart symptoms, because dangerous heart rhythms can occur before other symptoms.
Call 911 or go to the emergency room for chest pain, fainting, trouble breathing, choking, or a sudden change in mental state.
If you are thinking about harming yourself, call or text 988 (the Suicide and Crisis Lifeline) 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. A direct primary care doctor can coordinate your care and review your medicines. They can also refer you to a neurologist and other specialists.
Common questions
Is there a treatment for myotonic dystrophy?
There is no specific treatment for the progressive weakness in type 1. But other problems, such as cataracts and heart rhythm problems, can be treated.
Does myotonic dystrophy shorten life?
It can, depending on the form of type 1. Adults with the classic form may have a shorter life span. People with the mild form have a normal life span.
Can myotonic dystrophy be passed to children?
Yes. Both types are inherited in an autosomal dominant pattern. One changed copy of the gene is enough.
What is the difference between type 1 and type 2?
Type 2 tends to be milder than type 1. They are caused by changes in different genes.
Sources
- MedlinePlus Genetics - Myotonic dystrophy
- GeneReviews - Myotonic Dystrophy Type 1
- NINDS - Muscular Dystrophy
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.
