About Myotonic Dystrophy

Myotonic dystrophy is a genetic disease that affects 1 in 10,000 people. It can affect many parts of the body and can lead to significant physical and cognitive impairment and, in some cases, early death. Symptoms can include often debilitating muscle problems such as muscle weakness, trouble relaxing a muscle and muscle wasting that worsens over time. But the disease is also associated with a range of other symptoms that can affect a patient’s health and quality of life, including:

  1. difficulty with thinking and problem solving
  2. excessive daytime sleepiness
  3. nerve damage in feet and hands
  4. difficulty swallowing that can affect eating and speech
  5. pain and bloating after meals
  6. gastrointestinal problems
  7. gallstones
  8. enlarged colon
  9. heart rhythm problems and enlarged heart muscle
  10. low blood pressure

Myotonic dystrophy type I, also known as DM1, is the most common form of the disease. Adults with DM1 may eventually become physically disabled and loss of muscle control can make it difficult to perform simple physical tasks such as holding a cup, writing or opening a door. Loss of control in muscles in the mouth and throat can affect the ability to talk, eat and drink. If swallowing difficulties become extreme, patients may need to be fed through a feeding tube. The range and severity of symptoms of DM1 can make it difficult or impossible for many patients to work, care for themselves or their families, or live independently. Symptoms can progress to the point where they become life threatening. Babies born with the congenital form of DM1 are more severely affected and may experience life-threatening symptoms.

In many cases patients are not diagnosed until symptoms become severe and affect multiple organs including the heart, stomach, large intestine and brain. Diagnosis is confirmed though a diagnostic evaluation or genetic test.

Myotonic dystrophy can also take an emotional toll on both patients and caregivers. As symptoms progress, patients often experience limitations in their ability to perform many daily activities. Mobility may be limited and patients may require use of a cane, walker or wheelchair. Facial weakness or clumsiness can make it difficult for patients to be understood and cause feelings of anxiety or withdrawal in social settings. Many patients experience depression or a sense of loss and isolation. In many cases family members must take on expanded roles as caregivers, which can limit the ability to work. Myotonic dystrophy is a lifelong disease that typically requires long term care.

With no drugs approved for the treatment of DM1, patients are typically treated with drugs to address symptoms of the disease. Many patients also receive special education and speech and physical therapy.

Development & Clinical Trial Update

AMO has initiated a phase 2 clinical study in the United Kingdom for AMO-02 (tideglusib) for the treatment of myotonic dystrophy. This phase 2 exploratory study focuses on patients with congenital and juvenile onset myotonic dystrophy. This is the first sponsor-led clinical study evaluating an investigational therapy in this patient group as part of a development program. AMO Pharma is currently working to finalize plans for further global clinical trials.

More information on the Phase 2 clinical trial for AMO-02 in myotonic dystrophy can be found at https://clinicaltrials.gov/ct2/show/NCT02858908.

Resources for more information about myotonic dystrophy

There are several organizations available to provide information about myotonic dystrophy and the services available to help families:

Myotonic Dystrophy Foundation

Myotonic Dystrophy Support Group

Muscular Dystrophy Association

Muscular Dystrophy Association UK

In addition, many countries now have patient registries for myotonic dystrophy. For additional information on resources and to access a DM family and patient registry, please visit:

Norwood FL, Harling C, Chinnery PF, Eagle M, Bushby K, Straub V. Prevalence of genetic muscle disease in Northern England: in-depth analysis of a muscle clinic population. Brain. 2009 Nov;132(Pt 11):3175-86. PubMed PMID: 19767415; PubMed Central PMCID: PMC4038491.