More than 30 types of muscular dystrophy have been identified. They all cause problems with movement due to genetic mutations that lead to the inadequate production of proteins that your muscles need.

Muscular dystrophy is a group of inherited genetic conditions that cause progressive muscle weakness and often disability.

All types of muscular dystrophy are rare. Combined, they’re estimated to affect 1 in 3,000–8,000 people.

Let’s examine the most common subtypes of muscular dystrophy.

Duchenne muscular dystrophy is the most common type of muscular dystrophy and one of the most severe. It’s caused by a gene mutation on the X chromosome.

About 1 in 3,500 males are born with Duchenne muscular dystrophy. It’s much rarer in females since females have two X chromosomes, while males only have one. Only 2.5–20% of females who carry the gene develop symptoms.

The signs and symptoms, which generally appear in the first several years of life, can include:

The outlook for Duchenne muscular dystrophy is typically unfavorable, and most people with the condition need to use a wheelchair by age 12. Most people with this type of muscular dystrophy do not live past their 20s due to heart or lung issues.

Becker muscular dystrophy is caused by a recessive mutation on the X chromosome. “Recessive” means that the condition develops only if you receive the mutated gene from both parents. This type occurs almost exclusively in males and affects roughly 1 in 38,500 people in the United States.

Symptoms can begin at any time from ages 5–60. Some people with this condition can continue to walk until old age. Symptoms may include:

  • muscle weakness starting in your thighs
  • cramping with strenuous activity
  • cognitive impairment
  • delayed ability to run, jump, or climb stairs
  • enlarged calves
  • heart problems

People with Becker muscular dystrophy typically live to be 40–50 years old. Death usually occurs due to dilated cardiomyopathy.

Myotonic muscular dystrophy is the most common type of muscular dystrophy that begins in adulthood. It’s caused by autosomal dominant mutations in the DMPK or CNBP gene. “Autosomal” means the gene is located on one of the chromosomes not related to sex. “Dominant” means that you need to receive the gene from only one parent rather than both.

Myotonia is slowed relaxation after a normal muscle contraction. It’s commonly called muscle stiffness.

Myotonic muscular dystrophy generally affects about 1 in 3,000 people but is more common in some areas. In the Canadian province of Quebec, it occurs in about 1 in 500 people.

Severity can range from fatal in infancy to mild with no symptoms until late adulthood. It usually causes muscle weakness and an inability to relax the smaller muscles in your:

  • hands
  • face
  • neck

It can also cause symptoms such as:

An earlier age of onset is linked to a less favorable outcome and decreased survival. About half of people with the more severe type 1 eventually use a wheelchair, while most people with type 2 don’t need assistive mobility devices.

Limb-girdle muscular dystrophy is a group of muscular dystrophies that cause weakness primarily around your upper limbs, though it also affects your pelvic girdle (midsection) muscles. It occurs in 1 in 44,000–123,000 people. It can be inherited through more than 25 recessive or dominant genes.

Limb-girdle muscular dystrophy can start in childhood and cause symptoms that resemble those of Duchenne muscular dystrophy. But symptoms may not develop until adulthood and may progress slowly.

The outlook is highly variable between people. Some people maintain the ability to walk and may need to use a wheelchair only later in life.

Facioscapulohumeral muscular dystrophy (FMD) primarily causes muscle weakness and wasting of the muscles in your:

  • face
  • shoulders
  • upper arms
  • lower legs
  • pelvic girdle

FMD is inherited through a dominant mutation in the DUX4 gene. It’s thought to occur in about 1 in 10,000–25,000 people.

Symptoms usually start before age 20 but can begin later. FMD generally does not shorten life expectancy. Roughly 20% of people with FMD eventually use a wheelchair.

Emery-Dreifuss muscular dystrophy (EDMD) causes:

  • reduced range of motion in joints in early childhood
  • slowly progressing muscular weakness
  • muscle wasting starting in your upper arms and calves and later extending to your upper legs and shoulders

EDMD is usually caused by a dominant gene mutation on the X chromosome, though it can be autosomal dominant or autosomal recessive. It’s estimated to affect about 1 in 400,000 people.

The outlook varies, but many people live until at least middle age.

Distal muscular dystrophy is a group of conditions that cause progressive weakness in your:

  • hands
  • forearms
  • lower legs
  • feet

Many gene mutations can cause distal muscular dystrophy. The outlook varies widely between subtypes.

Congenital muscular dystrophy is thought to occur in slightly fewer than 1 in 100,000 people. It’s a group of muscular dystrophies, including Duchenne muscular dystrophy, that are present from birth or shortly after birth.

Oculopharyngeal muscular dystrophy symptoms usually appear between the ages of 40 and 60 years. It primarily causes progressive weakness of muscles around your eyes and throat.

The most common initial symptoms are drooping eyelids and trouble swallowing.

Oculopharyngeal muscular dystrophy can be caused by dominant or recessive genes. It usually does not affect life expectancy.

Collagen type VI-related disorders can be inherited through dominant or recessive genes.

Symptoms range from mild to severe. People with severe forms may never be able to run, jump, or climb stairs without using a railing. People with mild forms may remain independent for life.

Doctors use a variety of tests to diagnose muscular dystrophy, rule out other conditions, and monitor side effects. Possible tests include:

Here are some frequently asked questions people have about muscular dystrophy.

What causes muscular dystrophy?

Muscular dystrophy is usually caused by inherited gene mutations. In rare cases, these mutations can develop without a family history.

How many types of muscular dystrophy are there?

More than 30 types of muscular dystrophy have been identified. They’re classified based on factors such as:

  • age of onset
  • symptoms
  • associated genes
  • severity

What are the most common types of muscular dystrophy?

The most common type of muscular dystrophy is Duchenne muscular dystrophy.

What types of muscular dystrophy are most common in adults?

Myotonic dystrophy is the most common type of muscular dystrophy in adults.

What is the rarest type of muscular dystrophy?

Oculopharyngeal muscular dystrophy is one of the rarest types. It affects about 1 in 770,000 people.

What is the difference between muscular dystrophy and atrophy?

Muscle dystrophy is a genetic condition that causes progressive muscular weakness. Muscular atrophy is the loss of muscle mass. Atrophy can have many causes, including inactivity and a genetic condition called spinal muscular atrophy.

What disease is mistaken for muscular dystrophy?

Conditions that can cause similar symptoms to muscular dystrophy include:

  • spinal muscular atrophy
  • congenital myopathy
  • congenital myasthenic syndromes

All types of muscular dystrophy cause muscle weakness. The outlook varies widely. In some cases, the condition can be fatal within years, while in others it causes only mild symptoms late in life.

A doctor can help you figure out which type of muscular dystrophy you or your child has. They can also recommend management techniques to improve quality of life.