• Over the past few decades, the overall survival rate of Duchenne muscular dystrophy (DMD) has significantly improved.
• New treatments have helped increase the life expectancy of people living with DMD by nearly 10 years.
• The most common factors affecting life expectancy with DMD are heart and respiratory (breathing) problems.

Life expectancy for people living with Duchenne muscular dystrophy has significantly increased in recent years as new treatment options emerge. Among them are exon-skipping therapies that help address the gene mutations (changes) that cause this muscle-weakening disease.

In this article, we’ll discuss life expectancy with DMD and how different therapies are improving prognosis (outlook). We’ll also cover common complications that affect the outlook of those living with DMD.

What Is Duchenne Muscular Dystrophy?

DMD is a rare neuromuscular disorder diagnosed in early childhood that causes muscle weakness and degeneration that gets worse over time. DMD is caused by genetic changes in the dystrophin gene, which gives instructions to make dystrophin proteins. This protein is responsible for holding muscle cells together and helping them function properly. People with DMD don’t make enough dystrophin, which causes muscle symptoms.

DMD is the most common type of muscular dystrophy, affecting 4.8 per 100,000 people globally. The condition accounts for around half of all cases of muscular dystrophy. A milder form of muscular dystrophy known as Becker muscular dystrophy (BMD) — which affects 1.6 in 100,000 people globally — tends to affect teenagers and young adults.

Most symptoms of DMD develop in early childhood. Over time, people with DMD can develop other complications that affect their disease outlook, including lung and heart problems.

Common signs and symptoms of DMD include:

• Large calf muscles
• Toe-walking
• Learning difficulties
• Scoliosis (changes in spine curvature)
• Trouble breathing
• Difficulty walking, running, or climbing up stairs, leading to falls
• Waddling gait (waddling when walking)
• Gowers’ sign (standing up by crawling one’s hands up one’s legs)

Survival Rates With Duchenne Muscular Dystrophy

To better understand the disease outlook with DMD, it’s important to first learn about how researchers talk about survival and life expectancy. Many DMD studies talk about survival rates in terms of median overall survival (OS). Here we use this term to mean how long 50 percent of people with DMD remain alive.

As doctors and researchers have learned more about DMD and how to treat it, survival rates have significantly improved. Researchers from Sweden and Great Britain performed a meta-analysis of 14 different studies from around the world looking at people with DMD. They found that the median OS was 22 years.

The median OS could be divided further into different age groups:

• People born before 1970 had a median OS of just over 18 years.
• People born between 1970 and 1990 had a median OS of 24 years.
• People born after 1990 had a median OS of just over 28 years.

Researchers also found that the risk of death is very low for people with DMD who are 10 years old or younger. This study shows that survival rates for people living with DMD have improved over time.

Treatments for Duchenne Muscular Dystrophy Extend Life Expectancy

There’s currently no cure for DMD, but mainstay and new treatments continue to improve the quality of life for those living with DMD and extend their life expectancy. The therapies used to treat DMD today focus on managing symptoms and slowing disease progression.

Corticosteroids

One of the best ways to slow the progression of DMD is to start treatment with corticosteroids shortly after receiving a diagnosis. Corticosteroids are synthetic (laboratory-made) hormones that help control inflammation. In people with DMD, these drugs may help the body repair damaged or weakened muscle cells.

Studies show that corticosteroids help strengthen muscles in people with DMD. Long-term corticosteroid treatment can help reduce a person’s risk of losing their mobility and their risk of death by more than 50 percent.

One study of 86 people with DMD found that the OS rates improved significantly for participants treated with corticosteroids compared to those who weren’t. For example, the OS rate at 15 years for the corticosteroid group was 78.6 percent compared to 27.9 percent for those not treated with corticosteroids. This means that after 15 years, 78.6 percent of people treated with corticosteroids were alive, whereas 27.9 percent of people who weren’t treated with corticosteroids were alive.

The most commonly prescribed corticosteroids for treating DMD include prednisone and deflazacort (Emflaza). Corticosteroids work well to treat DMD, but they’re associated with some unwanted side effects. Overall, the benefits outweigh the risks, but side effects can include:

• Weight gain
• Delays in growth
• Osteoporosis (decline in bone density)
• Behavioral changes

Exon-Skipping Therapies

In recent years, scientists have developed new therapies for treating DMD that help address different mutations in the dystrophin gene. Many people living with this disease are missing a specific part of DNA known as an exon — this means that their cells don’t have all of the instructions needed to make dystrophin proteins.

New treatments known as exon-skipping therapies help correct this problem so that muscle cells can make more dystrophin. The U.S. Food and Drug Administration (FDA) has approved several different exon-skipping therapies, including:

• Exondys 51, a formulation of eteplirsen
• Vyondys 53, a formulation of golodirsen
• Viltepso, a formulation of viltolarsen
• Amondys 45, a formulation of casimersen

One study found that treatment with eteplirsen improved median OS rates by 5.4 years. Researchers found that 50 percent of people who were treated with eteplirsen lived for nearly 33 years, compared to 27.4 years for those who weren’t treated with eteplirsen.

It’s important to note that many of these treatments are new and haven’t been studied long-term, so we don’t know their effects on life expectancy yet.

Complicating Factors in Survival With Duchenne Muscular Dystrophy

Dystrophin helps the lungs and heart work properly — without it, there’s a higher risk of health complications. People with DMD often have weakened lung and heart muscles, which makes it hard to breathe. The most common complications and causes of death in people with DMD are:

• Heart failure — A condition that prevents your heart from pumping blood around the body
• Respiratory failure — A condition that prevents your lungs from taking in enough oxygen on their own
• Pneumonia — A bacterial infection that affects the lungs
• Aspiration — Breathing in food or another foreign object into the lungs

Fortunately, there are treatments available to help prevent these complications. Your child or loved one’s doctor will likely prescribe medications or respiratory care as needed. Beta-blockers or ACE inhibitors are medications used to help take stress off of the heart and help it pump blood better. Studies show that these medications can help people with DMD live longer when they’re prescribed early.

Medical devices can also help people with DMD breathe better during the day and at night, depending on their needs. There are many types of ventilation to help bring air into the lungs — other devices help them cough and clear out mucus to keep the lungs clear. Studies show that using ventilation while sleeping has improved life expectancy.

Find Your Team

At myDMDcenter, the site for people with Duchenne muscular dystrophy and their loved ones, people come together to gain a new understanding of DMD and share their stories with others who understand life with DMD.

Have you talked to your or your loved one’s doctor about life expectancy with DMD? Share your experiences in the comments below.