Myotonic dystrophy type 3 and type 4 (DM3 & DM4) are possibly two other forms of myotonic dystrophy. There are a small number of people with symptoms fitting a diagnosis of myotonic dystrophy but who do not have mutations in the genes which cause DM1 and DM2. At this time, medical researchers and specialists are uncertain whether these are truly new forms of myotonic dystrophy. It may be that mutations or changes in other genes may cause these unique forms. It may also be that these individuals actually have a different condition but have a unique presentation (different symptoms than normally seen in that condition).
In general, symptoms of myotonic dystrophies may include progressive muscle loss and weakness, particularly in the lower legs, hands, neck, and face. People with myotonic dystrophy often have prolonged muscle tensing (myotonia) and are not able to relax certain muscles after use. The symptoms may vary greatly even within the same family.
Although a diagnosis is very important, even with a diagnosis of DM1 or DM2, it may be difficult to make predictions of how the condition will affect your life over time since the condition can affect each person differently. It is therefore very important to learn as much as you can about myotonic dystrophy, the different types and the different symptoms and complications you may experience. You will most likely need to see a number of different specialist - understanding who is the best doctor to see for your different symptoms is very important. If you have been diagnosed with DM3 or DM4, talk with your doctor about which specialists you should see. Connecting with a support organization is often a great way to learn more about your diagnosis and how to get the treatment and care you may need.