Our Muscular Dystrophy Association (MDA) supported program offers hope through advanced medicine, research and the support of one of the finest muscular dystrophy specialty teams available.
Muscular dystrophy is made up of more than 30 genetic diseases which affect the neuromuscular system and gradually weaken the body's muscles. Your child's treatment and activities will depend on the type of MD they've been diagnosed with, and at what age. Those with milder forms of the disease may live a normal life with hardly any symptoms. Even for those kids diagnosed with severe forms of MD, newer, more advanced medical care is helping them to live longer with a better quality of life.
What are the different types of muscular dystrophy?
The different types of muscular dystrophy affect different sets of muscles and result in different degrees of muscle weakness.
Duchenne muscular dystrophy
Duchenne muscular dystrophy is the most common and the most severe form of muscular dystrophy. It affects about 1 out of every 3,500 boys. (Girls can carry the gene that causes the disease, but they usually have no symptoms.) This form occurs because of a problem with the gene that makes dystrophin. Without this protein, the muscles break down and a child becomes weaker.
In cases of Duchenne muscular dystrophy, symptoms usually appear around age 5, as the pelvic muscles begin to weaken. Most kids with this form need to use a wheelchair by age 12. Over time, their muscles weaken in the shoulders, back, arms, and legs.
Eventually, the respiratory muscles are affected, and a ventilator is required to assist breathing. Kids who have Duchenne muscular dystrophy typically have a life span of about 20 years.
Although most kids with Duchenne muscular dystrophy have average intelligence, about a third experience learning disabilities and a small number are intellectually disabled.
While the incidence of Duchenne is known, it's unclear how common other forms of muscular dystrophy are because the symptoms can vary so widely between individuals. In fact, in some people the symptoms are so mild that the disease goes undiagnosed.
Becker muscular dystrophy
Becker muscular dystrophy is similar to Duchenne, but is less common and progresses more slowly. This form of muscular dystrophy is caused by insufficient production of dystrophin.
Symptoms begin during the teen years, then follow a pattern similar to Duchenne muscular dystrophy. Muscle weakness first begins in the pelvic muscles, then moves into the shoulders and back. Many children with Becker muscular dystrophy have a normal life span and can lead long, active lives without the use of a wheelchair.
Myotonic dystrophy, also known as Steinert's disease, is the most common adult form of muscular dystrophy, although half of all cases are diagnosed in people under 20 years old. It is caused by a portion of a particular gene that is larger than it should be. The symptoms can appear at any time during a child's life.
The main symptoms include muscle weakness, myotonia (in which the muscles have trouble relaxing once they contract), and muscle wasting (when the muscles shrink over time). Kids with myotonic dystrophy also can experience cataracts and heart problems.
Limb-girdle muscular dystrophy
Limb-girdle muscular dystrophy affects boys and girls equally. Symptoms usually start when kids are between 8 and 15 years old. This form progresses slowly, affecting the pelvic, shoulder, and back muscles. The severity of muscle weakness varies — some kids have only mild weakness while others develop severe disabilities and as adults need to use a wheelchair.
Facioscapulohumeral muscular dystrophy
Facioscapulohumeral muscular dystrophy can affect both boys and girls, and the symptoms usually first appear during the teen years. It tends to progress slowly.
Muscle weakness first develops in the face, making it difficult for a child to close the eyes, whistle, or puff out the cheeks. The shoulder and back muscles gradually become weak, and kids have difficulty lifting objects or raising their hands overhead. Over time, the legs and pelvic muscles also may lose strength.
Who gets it?
Some forms of muscular dystrophy are seen in infancy or childhood, while others may not appear until middle age or later. The disorders differ in terms of the distribution and extent of muscle weakness (some forms of muscular dystrophy also affect cardiac muscle), age of onset, rate of progression, and pattern of inheritance.
Duchenne muscular dystrophy
Duchenne muscular dystrophy is the most common form of muscular dystrophy and primarily affects boys. It is caused by the absence of dystrophin, a protein involved in maintaining the integrity of muscle. Onset is between 3 and 5 years and the disorder progresses rapidly. Most boys are unable to walk by age 12, and later need a respirator to breathe. Girls in these families have a 50 percent chance of inheriting and passing the defective gene to their children.
Becker muscular dystrophy
Becker muscular dystrophy affects about 1 in 30,000 boys and typically begin in the teen years. Boys with Becker muscular dystrophy (very similar to but less severe than Duchenne muscular dystrophy) have faulty or not enough dystrophin.
Facioscapulohumeral muscular dystrophy
Facioscapulohumeral muscular dystrophy usually begins in the teenage years. It causes progressive weakness in muscles of the face, arms, legs, and around the shoulders and chest. It progresses slowly and can vary in symptoms from mild to disabling.
Myotonic muscular dystrophy
Myotonic muscular dystrophy is the disorder's most common adult form. But approximately 50 percent of all cases are diagnosed before the age of 20 years. It is typified by prolonged muscle spasms, cataracts, cardiac abnormalities, and endocrine disturbances. Individuals with myotonic muscular dystrophy have long, thin faces, drooping eyelids, and a swan-like neck.
Limb-girdle muscular dystrophy
This type of MD affects both girls and boys. Symptoms typically begin between the ages of 8 and 15 years.
What are the symptoms?
A child who is diagnosed with MD gradually loses the ability to do things like walk, sit upright, breathe easily, and move the arms and hands. This increasing weakness can lead to other health problems.
There are several major forms of muscular dystrophy, which can affect the muscles to varying degrees. In some cases, MD starts causing muscle problems in infancy; in others, symptoms don't appear until adulthood.
Many kids with muscular dystrophy follow a normal pattern of development during their first few years of life. But in time common symptoms begin to appear. A child who has MD may start to stumble, waddle, have difficulty going up stairs, and toe walk (walk on the toes without the heels hitting the floor). A child may start to struggle to get up from a sitting position or have a hard time pushing things, like a wagon or a tricycle.
Kids with MD often develop enlarged calf muscles (called calf pseudohypertrophy) as muscle tissue is destroyed and replaced by fat.
How is it diagnosed?
When first suspecting that a child has muscular dystrophy, your doctor will do a physical exam, take a family history, and ask about any problems — particularly those affecting the muscles — that your child might be having.
In addition, your doctor may perform tests to determine what type of MD is involved and to rule out other diseases that could cause the problem. These might include a blood test to measure levels of serum creatine kinase, an enzyme that's released into the bloodstream when muscle fibers are deteriorating. Elevated levels indicate that something is causing muscle damage.
Your doctor may also do a blood test to check your child’s DNA for gene abnormalities, and often times a muscle biopsy is done to look for patterns of deterioration and abnormal levels of dystrophin, a protein that helps muscle cells keep their shape and length.
How is it treated?
There is no cure for MD, but our researchers are working closely with the Muscular Dystrophy Association and other pediatric researchers across the country and around the globe to learn more about how to prevent and treat MD. The neurospecialists here at Cook Children’s are also working on improving muscle and joint function and slowing muscle deterioration so that your child has every opportunity available to live as actively and independently as possible.
If your child is diagnosed with MD, a team of medical specialists will work with you and your family, including a:
- Physical and occupational therapists
- Nurse practitioner
- Registered dietitian
- Social worker
Muscular dystrophy is often degenerative, so kids may pass through different stages as it progresses and require different kinds of treatment. During the early stages, physical therapy, joint bracing, and medications are often used.
During the later stages, your doctor may recommend assistive devices such as:
- Physical therapy and bracing to improve flexibility
- Power wheelchairs and scooters to improve mobility
- Ventilator to support breathing
- Robotics to help your child perform routine daily tasks
Our Home Health specialists will work with you, your child and your medical team to assure access to the right devices for your child.
Physical Therapy and Bracing
Physical therapy can help your child maintain muscle tone and reduce the severity of joint contractures with exercises that keep your child’s muscles strong and their joints flexible.
Bracing is also used since it may help prevent joint contractures, a stiffening of the muscles near the joints that can make it harder to move and can lock the joints in painful positions. By providing extra support in just the right places, bracing can extend the time that your child can walk independently.
If your child has been diagnosed with Duchenne muscular dystrophy, your doctor may prescribe the steroid prednisone to help slow the rate of muscle deterioration. By doing so, your child may be able to walk longer and live a more active life.
There is some debate over the best time to begin prednisone treatment, but most doctors prescribe it when a child is 5 or 6 years old or when the child's strength begins to significantly decline. Prednisone does have side effects, though. It can cause weight gain, which can put even greater strain on already weak muscles. It also can cause a loss of bone density and, possibly, lead to fractures. If prescribing prednisone, your doctor will closely monitor your child.
Many children with the Duchenne and Becker forms of MD develop severe scoliosis — an S- or C-shaped curvature of the spine caused by back muscles that are too weak to hold the spine erect.
Some kids with severe cases undergo spinal fusion, a surgery that can reduce pain, lessen the severity of the curvature so that your child can sit upright and comfortably in a chair, and ensure that the spine curvature doesn't have an effect on breathing. Usually, spinal fusion surgery only requires a short hospital stay.
Many kids with MD also have weakened heart and respiratory muscles. As a result, they can't cough out phlegm and sometimes develop respiratory infections that can quickly become serious. Good general health care and regular vaccinations are especially important for children with muscular dystrophy to help prevent these infections.
A variety of new technologies can provide independence and mobility for kids with muscular dystrophy.
Some kids with Duchenne MD might use a manual wheelchair once it becomes difficult to walk. Others go directly to a motorized wheelchair, which can be equipped to meet their needs as muscle deterioration advances.
Robotic technologies also are under development to help kids move their arms and perform activities of daily living.
If your child would benefit from an assistive technological device, our Muscular Dystrophy Association Clinic team is here help. We can also discuss financial assistance that might be available through the Muscular Dystrophy Association. In some cases, health insurers cover the cost of these devices.
Searching for a cure
Our neurosciences team is actively involved in research and clinical trials in the hope to prevent and cure kids with muscular dystrophy. If you would like to learn more about current research and available clinical trials, we invite you to talk to us about it.