What is Myotonic Dystrophy?

Myotonic dystrophy (DM) is a complex, inherited disorder that primarily results in progressive muscle atrophy and weakness. Individuals with the disease tend to have delayed muscle contractions (myotonia). They are unable to relax specific muscles after contracting them.

Myotonic dystrophy (DM) has numerous and varied symptoms. It may impact various systems within your body, such as your:

• Skeletal and heart muscles.
• Eyes.
• Cardiovascular system.
• Endocrine system.
• Central nervous system.
• Two forms of myotonic dystrophy exist.

Myotonic dystrophy type 1 (DM1), or Steinert disease, has four forms: classic, mild, congenital, and childhood.

Myotonic dystrophy type 2 (DM2), or proximal myotonic myopathy.

They have similar symptoms, but DM2 is less severe than DM1.

How is Muscular Dystrophy different from Myotonic Dystrophy?

Muscular dystrophy is a group of more than 30 inherited (genetic) muscle conditions that cause progressive muscle weakness. Muscular dystrophies are a group of myopathies, diseases affecting your skeletal muscles. Your muscles get smaller and weaker over time. This makes it hard to walk and do everyday things. It may also harm your heart and lungs.

Myotonic dystrophy is a form of muscular dystrophy. It's the most prevalent adult-onset form of muscular dystrophy. (But some forms of myotonic dystrophy start in infancy or childhood.)

Who does myotonic dystrophy impact?

Various forms of myotonic dystrophy start at various ages:

• Classic myotonic dystrophy type 1: This type typically starts in your 20s, 30s or 40s.
• Mild myotonic dystrophy type 1: This form affects people 20 to 70 years old (typically after the age of 40).
• Congenital myotonic dystrophy type 1: This form affects infants (“congenital” means “present at birth”).
• Childhood myotonic dystrophy type 1: This form typically begins around age 10.
• Myotonic dystrophy type 2: This form typically begins in adulthood. The average age of onset is 48 years.

What are the Symptoms of myotonic dystrophy?

In myotonic dystrophy, the smaller muscles, such as those in the hands, face, neck, and jaw, are typically involved first. Symptoms may occur at any time between birth and old age.

Other symptoms may be:

• Muscle stiffness (myotonia)
• Clouding of the eye lens (cataracts)
• A slow and irregular heartbeat (cardiac arrhythmia)
• Slurred speech
• Dysphagia (swallowing difficulties)
• Bowel difficulties such as diarrhea, constipation, and incontinence
• Behavioral and personality difficulties
• Excessive sleepiness or tiredness

Everyone with myotonic dystrophy will experience different variations and severity of symptoms. It’s likely the symptoms will get worse very slowly. The condition may become worse as it’s passed down through the generations.

If you have a mild form of myotonic dystrophy with little or no symptoms, you might not experience significant disability.

Your heart rate will need to be checked for changes. This is because there's a risk of the electrical impulses that regulate your heartbeat moving too slowly through your heart.

Life expectancy varies for individuals with myotonic dystrophy. Most people have a normal life expectancy. Individuals with the more severe congenital form that occurs at birth may die at a very young age.

Individuals whose symptoms start in childhood or adolescence may experience a reduced life expectancy. Pneumonia, respiratory difficulty, or cardiac difficulty is often the mode of death in most instances of myotonic dystrophy.

You should inform any healthcare practitioners you visit that you have myotonic dystrophy, as it can interfere with general anesthesia.

Myotonic Dystrophy 2 (DM2)

There are 2 forms of myotonic dystrophy, DM1 and DM2. Type 1 is more severe and occurs more often than type 2.

DM2 has the same symptoms as DM1. DM2 leads to weakness in muscles near the joints (proximal muscles), such as in the:

• Shoulders
• Hips

A person with DM2 may have cataracts or cardiac issues, but they're normally less severe compared to DM1. Facial weakness and myotonia (difficulty relaxing muscles) are typically mild or not noticeable at all.

What causes Myotonic Dystrophy?

Myotonic dystrophy (DM) is genetic (inherited from parent to biological child).

Mutations (changes) in the DMPK gene lead to myotonic dystrophy type 1, and mutations in the CNBP gene lead to type 2.

These same kinds of changes in the DMPK and CNBP genes cause myotonic dystrophy types 1 and 2. In both conditions, part of the DNA is abnormally repeated many times, creating a region of instability in the gene. The more times the DNA is abnormally repeated, the worse the symptoms of DM will be.

Excessive messenger RNA from diseased DNA repeats has been shown to be harmful and to interfere with the synthesis of many proteins in cells, resulting in manifestations and symptoms across several organs in myotonic dystrophy.

Myotonic Dystrophy Inheritance

Both forms of myotonic dystrophy have an autosomal dominant inheritance pattern. If an autosomal dominant trait is involved, one only needs to look to one of the parents to carry on the condition. Fifty percent of the children of a biological parent carrying an autosomal trait will inherit that trait.

As myotonic dystrophy type 1 is passed from one generation to the next, the condition generally begins earlier and earlier in life, and signs and symptoms become more severe. This phenomenon is called anticipation.

How is Myotonic Dystrophy diagnosed?

If you’re experiencing symptoms of myotonic dystrophy (DM), a healthcare provider will perform a physical exam and ask questions about your:

• Personal medical history.
• Family medical history, especially a history of DM.
• Symptoms.
• Some medical tests can help diagnose myotonic dystrophy.

What are the tests done to Diagnose Myotonic Dystrophy?

Genetic testing can diagnose myotonic dystrophy (DM). The test seeks mutations in the DMPK gene (in DM1) or the CNBP gene (in DM2).

If your doctor is not sure whether you might have DM or another illness, they might order one or more of the following tests before they recommend genetic testing:

• Creatine kinase blood test: Creatine kinase is an enzyme that is primarily found in your heart and skeletal muscle. Your skeletal muscle cells or heart muscle cells release creatine kinase into your blood when they're injured. In individuals with mild myotonic dystrophy, it might be slightly increased but is usually normal.
• Electromyogram (EMG): The test consists of a check of the electrical activity of the muscle fibers by means of a thin needle electrode that's placed in your muscles. The muscles of most individuals with myotonic dystrophy exhibit excess waxing and waning electrical activity even at rest.
• Muscle biopsy: To do a muscle biopsy, a health care provider will take a small amount of tissue and cells from one of your muscles. They will examine it under a microscope for evidence of DM.

If the tests do indicate a diagnosis of DM, your doctor will probably order additional tests to evaluate the function of some of the organs that DM can harm. These tests are:

• An electrocardiogram to test your heart function.
• Pulmonary (lung) function test to screen for neuromuscular respiratory failure.
• Sleep study to screen for obstructive sleep apnea and hypersomnia (daytime sleepiness).

How is Myotonic Dystrophy treated?

There is no cure for myotonic dystrophy (DM). Treatment, however, is aimed at:

• Controlling symptoms.
• Optimizing quality of life and independence.
• DM can involve so many different body areas. Depending on your symptoms, treatment may involve:
• Medications that decrease prolonged myotonia, including sodium channel blockers such as mexiletine, tricyclic antidepressants, benzodiazepines or calcium antagonists.
• A CPAP machine for sleep apnea.
• Neurostimulants like methylphenidate for excessive daytime sleepiness.
• Cataract surgery for cataracts that cloud your eyes.

Treatment for diabetes, which can include drugs in pill form and/or insulin. Individuals with DM are at higher risk of diabetes due to insulin resistance.

Synthetic testosterone for treating low testosterone (male hypogonadism). Males with DM1 often have low testosterone and erectile dysfunction.

Physical and occupational therapy are important components of optimizing independence for individuals with DM. It may strengthen your muscles and assist you in learning new methods of accomplishing daily activities. Assistive devices, like braces, canes or a wheelchair, can also aid independence.

Speech-language pathology (SLP) can assist with swallowing difficulty (dysphagia) and slurred speech (dysarthria).

Can myotonic dystrophy be prevented?

Since myotonic dystrophy (DM) is a genetic disorder, there's nothing you can do to avoid it.

If you're worried about passing on DM or other genetic disorders before attempting to have a biological child, discuss genetic counseling with your healthcare provider.

What is the Prognosis of Myotonic Dystrophy?

The prognosis (outlook) of myotonic dystrophy (DM) depends on the type and the age it begins. An earlier age of symptom onset is generally associated with poorer outcomes and reduced survival rates.

Up to 50% of people with myotonic dystrophy type 1 need a wheelchair for mobility before death. People with myotonic dystrophy type 2 have milder symptoms and typically don’t need assistive devices for mobility.

What is the life expectancy of an individual with myotonic dystrophy?

The average life expectancy for myotonic dystrophy varies based on the type.

The neonatal mortality rate (death within 28 days after birth) is approximately 18% in infants with congenital DM1.

Approximately 25% of individuals with congenital DM1 die within the first 18 months of life and 50% die in their mid-30s.

Individuals with mild DM1 typically have normal life expectancy. Life expectancy is shorter than average in typical DM1.

When should I talk to my healthcare provider about myotonic dystrophy?

If you're having DM symptoms, like muscle weakness or myotonia, speak with a healthcare provider.

If you have DM, you'll need to see your healthcare team regularly to ensure your current regimen remains effective.

Why choose Tender Palm Super Specialty Hospital for Myotonic Dystrophy treatment in Lucknow, India?

Tender Palm Super Speciality Hospital offers advanced treatment for Myotonic Dystrophy in Lucknow, India, at an affordable cost. We have a team of experienced neurologists, neuromuscular specialists, genetic disorder experts, and rehabilitation specialists who provide accurate diagnosis, personalized care, and advanced treatment for Myotonic Dystrophy. Our neurosciences team has extensive experience in successfully treating Myotonic Dystrophy in Lucknow, India.

To seek an Expert Consultation for Myotonic Dystrophy treatment in Lucknow, India:

Call us at +91-9076972161
Email at care@tenderpalm.com

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