Myotonic Dystrophy: Frequently Asked Questions

Myotonic dystrophy (DM) is a muti-systemic inherited disease that affects 1 in 8,000 people or 40,000 individuals in the US alone. Although often viewed as a muscle disease, this description is misleading. Individuals affected by DM may have many different types of issues, including skeletal muscle problems, heart function abnormalities, breathing difficulties, cataracts, issues with speech and swallowing (dysarthria and dysphagia), cognitive impairment, excessive daytime sleepiness, or diabetic symptoms. ...

Muscular dystrophy (MD) refers to a group of nine genetic diseases that cause progressive weakness and degeneration of muscles used during voluntary movement. Myotonic dystrophy is one of the muscular dystrophies. It is the most common form seen in adults and is suspected to be among the most common forms overall.

Myotonic dystrophy has been referred to by different names over the years: Myotonic muscular dystrophy - often abbreviated as MMD Myotonia atrophica - a Latin name, not commonly used Dystrophia myotonica - a Latin name used by many doctors; often abbreviated as DM. The different types of DM are often referred to as DM1, DM2, or DM3. DM1 is also known as Steinert's Disease, named for the German doctor who first identified this disorder in 1909. DM2 is also known as Proximal myotonic myopathy or PROMM. ...

Myotonic dystrophyis a progressive or degenerative disease. Symptoms tend to worsen gradually over several decades. While no treatment exists that slows the progression of myotonic dystrophy, management of its symptoms can greatly improve patient quality of life. Early intervention can reduce or avert complications that sometimes arise. DM2 tends to be less severe than DM1 and has minimal impact on life expectancy. DM1 is much more variable and the prognosis for an affected individual is difficult to predict. ...

A complete diagnostic evaluation, which includes family history, physical examination, and medical tests, is typically required for a presumptive diagnosis of myotonic dystrophy. The presence of the disorder can then be confirmed by genetic testing. The genetic test requires a sample of blood from the patient. The DNA is then extracted from the blood and analyzed to see if that person has the mutation that causes myotonic dystrophy. ...

There are two well-defined types of the disease (DM1 and DM2) which have distinct but overlapping symptoms. Both DM1 and DM2 are characterized by muscle weakness and myotonia, heart abnormalities, cataracts and insulin resistance. In general, DM2 is less severe than DM1: fewer systems are affected, patients develop the disease only as adults, and the disorder’s impact on everyday life is relatively less disruptive. In contrast, DM1 can occur from birth to old age. ...

MDF actively supports research leading to the development of a cure for myotonic dystrophy. Please click here for more information on how you can get involved.

Myotonic dystrophy (DM) is an inherited disease where a change (called a mutation) has occurred in a gene required for normal muscle function. The mutation prevents the gene from carrying out its function properly. The change is an autosomal dominant mutation, which means one copy of the altered gene is sufficient to cause the disorder. As a result, affected individuals have a 50% chance of passing on the mutated gene to their children. A child is equally likely to have inherited the mutated gene from either parent. ...