Did you know there are several types of muscular dystrophy, each with unique features? Muscular dystrophy is a group of genetic (inherited) muscle diseases that cause muscle weakness, but the way it develops can vary widely. Some forms appear in early childhood, while others don’t show up until adulthood.

Each type of muscular dystrophy may differ based on several factors, including:

• How it’s inherited
• Which genes are involved
• Which muscle groups are affected
• When signs and symptoms begin
• How fast it progresses
• Severity of muscle weakness

What Causes Muscular Dystrophy?

Before learning about the different types of muscular dystrophy, it’s helpful to understand how muscular dystrophy is inherited — that is, how it can be passed from parents to their children through genes.

Almost all cases of muscular dystrophy are caused by genes that are passed down by your biological parents. There are different ways you can inherit genetic mutations (changes). Different types of muscular dystrophy are associated with different inheritance patterns.

Some types of muscular dystrophy need only one parent to pass down a genetic mutation — this is called dominant inheritance. If both parents pass down a genetic mutation, it’s called recessive inheritance.

Other types of muscular dystrophy are associated with genetic mutations on the X chromosome, a sex chromosome. This is called sex-linked or X-linked inheritance. According to Cleveland Clinic, people who are genetically male only have one copy of the X chromosome. People who are genetically female have two copies of the X chromosome.

The Muscular Dystrophy Association (MDA) notes that the types of muscular dystrophy with X-linked inheritance are more common in males. Because males have only one copy of the X chromosome, they only need to inherit a genetic mutation from their biological mother. Most females with an abnormal gene don’t have any symptoms of muscular dystrophy but are considered carriers of the disease.

Researchers have found more than 30 types of muscular dystrophy. This article reviews the nine most common types.

1. Duchenne Muscular Dystrophy

Duchenne muscular dystrophy (DMD) is the most common type of muscular dystrophy diagnosed in children. It affects about 6 per 100,000 people in North America and Europe.

The MDA has found that DMD mostly affects boys because it’s inherited through an X-linked inheritance pattern. People with DMD have a mutation in the dystrophin gene, a gene that provides instructions for making a protein called dystrophin. Dystrophin helps to protect your muscle fibers and keep them working properly. Genetic mutations that cause DMD result in a lack of working dystrophin protein.

DMD symptoms typically start early in life, around age 2 or 3. Muscle weakness gets worse over time. It usually affects the muscles near the core of the body before affecting the limbs. NYU Langone Health, an academic medical center in New York City, notes that most boys diagnosed with DMD are unable to walk and need a wheelchair by age 12. As DMD progresses, muscle weakness can begin to affect the muscles in the heart and lungs. Other parts of the body that can be affected include:

• Spine
• Throat
• Stomach
• Intestines

With treatment, many people with DMD can live to adulthood and into their 30s.

2. Becker Muscular Dystrophy

Becker muscular dystrophy (BMD) is a type of muscular dystrophy similar to DMD. Like DMD, BMD is caused by abnormalities in the dystrophin gene. However, the genetic mutations that cause BMD usually result in a dystrophin protein that’s still partly functional. This means that BMD doesn’t progress as quickly or severely as DMD. The MDA points out that BMD mostly affects males because it’s also inherited in an X-linked inheritance pattern.

Compared to DMD, people with BMD are usually diagnosed at an older age, between 12 and 25 years. However, some are diagnosed with BMD as late as 60 years old.

The course of BMD isn’t as predictable as in DMD. Some people with BMD can have close to a normal life expectancy if they don’t have severe cardiomyopathy (heart muscle deterioration). The average lifespan for people with BMD-related heart problems is 47.3 years.

3. Myotonic Dystrophy

Myotonic dystrophy is a type of muscular dystrophy that’s most commonly diagnosed in adults. You may see myotonic dystrophy abbreviated as DM, referencing its Greek name, dystrophia myotonica. This type of muscular dystrophy mainly affects your ability to relax voluntary muscles — the ones you control, such as those in your arms, legs, face, neck, and torso.

There are two types of myotonic dystrophy — type 1 (DM1) and type 2 (DM2) — which are caused by different genetic mutations.

It’s estimated that about 10 in every 100,000 people have myotonic dystrophy. Unlike DMD and BMD, myotonic dystrophy affects males and females equally, per the Centers for Disease Control and Prevention (CDC). This is because myotonic dystrophy is passed down through a dominant inheritance pattern. Only one copy of the mutated gene from one parent is needed to develop this condition.

Myotonic dystrophy is usually diagnosed between the ages of 10 and 30 and often progresses gradually. Muscle weakness typically begins in the face, neck, arms, and legs. Over time, myotonic dystrophy can affect other parts of the body, including the:

• Heart
• Lungs
• Eyes
• Digestive tract
• Hormone-producing organs — These include the thyroid, pancreas, adrenal glands, and reproductive organs like the ovaries or testes.

Life expectancy in myotonic dystrophy is usually lower than in the general population but depends on the type and how severe the disease is.

4. Limb-Girdle Muscular Dystrophy

Limb-girdle muscular dystrophy (LGMD) is a type of muscular dystrophy that affects the muscles around the hips and shoulders. There are 33 different types of LGMD.

Different types of LGMD can be inherited in a recessive or dominant inheritance pattern. LGMD can also develop from a new genetic mutation in people without a family history of the disease.

LGMD affects about 2 people per every 100,000 people and can affect anyone, regardless of biological sex. The age of onset and severity of LGDM depends on the specific type. When LGMD begins in childhood, it may cause more severe symptoms with a faster progression compared to people who develop the disease in adulthood.

Some types of LGMD may also cause additional symptoms, such as:

• Heart and breathing problems
• Joint stiffness
• Muscle cramps
• Enlarged calf muscles
• Problems with the muscles that control the hands and feet

5. Facioscapulohumeral Muscular Dystrophy

Facioscapulohumeral muscular dystrophy (FSHD) is a type of muscular dystrophy that affects the muscles of the face, shoulders, and upper arms.

FSHD affects about 4 people in every 100,000 people. The condition is passed down in a dominant inheritance pattern, and according to the CDC, it affects males and females equally. A spontaneous genetic mutation can also cause FSHD.

Most people with FSHD experience symptoms before the age of 20. FSHD doesn’t usually affect the heart or breathing muscles. FSHD symptoms often progress slowly and don’t usually affect the life expectancy of those living with this condition.

6. Congenital Muscular Dystrophy

Congenital muscular dystrophy (CMD) is a group of more than 30 types of muscular dystrophy. Different CMDs are caused by different gene mutations and affect different muscle groups.

CMD affects about 1 in every 100,000 people, with males and females equally affected, per the CDC. All types of CMDs cause symptoms before age 2 and often right after birth. How severe and fast CMD progresses depends on the type. Some kinds of CMD can also affect life expectancy.

CMD symptoms vary by type but generally cause progressive muscle weakness and joint problems. Some types of CMD can also cause symptoms such as:

• Scoliosis (curved spine)
• Breathing problems
• Intellectual and learning disabilities
• Eye problems
• Seizures

7. Distal Muscular Dystrophy

Distal muscular dystrophy (DD) affects the distal muscles. These muscles are those farthest away from the center of the body, including the hands, feet, and lower arms and legs.

Fewer than 1 person per 100,000 has been diagnosed with DD. There are several different types of DD. Each different type of DD is caused by a different genetic mutation and can have different symptoms. Some types are inherited in a recessive inheritance pattern, while others have a dominant inheritance pattern. According to the CDC, DD affects males and females equally.

DD symptoms usually begin in childhood or early adulthood and start with the distal muscles. Over time, DD can cause muscle wasting and affect mobility. In some people, DD can affect other muscle groups, such as the heart and those used for swallowing and speaking.

8. Oculopharyngeal Muscular Dystrophy

Oculopharyngeal muscular dystrophy (OPMD) affects the muscles that control the eyes and throat.

Fewer than 1 person in every 100,000 has OPMD. Although OPMD is rare, it’s more common in certain groups of people, including people who are Ashkenazi Jewish, French Canadian, or Hispanic, according to NYU Langone Health.

Most people with OPMD inherit the condition from one parent (dominant inheritance pattern). However, in rare cases, genetic mutations that cause OPMD are inherited with a recessive inheritance pattern. Because OPMD is mostly passed down by one parent, the number of males and females with the condition is about the same, per the CDC.

Most people with OPMD begin to see symptoms later in life, in their 40s or 50s. Drooping eyelids and difficulty swallowing are the most common symptoms of OPMD. Symptoms usually progress slowly. Over time, some people with OPMD may have mobility problems if they develop muscle weakness in their shoulders, legs, or hips.

9. Emery-Dreifuss Muscular Dystrophy

Emery-Dreifuss muscular dystrophy (EDMD) affects the muscles of the shoulders, upper arms, lower legs, and heart.

Fewer than 1 person in every 100,000 has EDMD. More males are affected by EDMD than females, according to the CDC. This is because EDMD is most commonly passed down through an X-linked inheritance pattern. However, EDMD can also be inherited through a dominant or recessive inheritance pattern.

EDMD symptoms usually begin in early childhood by age 10 and progress slowly. However, muscle weakness may not cause any serious problems until later in life. Many people with EDMD will have heart problems by the age of 20.

Talk to Your Doctor

Early diagnosis and the right care can make a big difference in managing symptoms and improving quality of life. Research is ongoing, with scientists working toward better treatments. If you or someone you know is living with muscular dystrophy, a health care provider can help connect you with the right care and support.

Find Your Team

On myMDteam, the site for people with muscular dystrophy and their loved ones, people come together to gain a new understanding of muscular dystrophy and share their stories with others who understand life with the condition.

Which type of muscular dystrophy has affected you or your family? Do you have questions for others? Share your experiences in the comments below or by posting to your Activities page.