Myotonic Dystrophy Foundation

The path to a correct diagnosis of myotonic dystrophy (DM) can be long and complex. Typically, a combination of clinical observation and medical tests leads to a presumptive diagnosis of myotonic dystrophy, which is then confirmed through genetic testing.

During diagnosis, the number of potential causes that must be considered is high. The symptoms of rare disorders such as myotonic dystrophy often mimic more common diseases, which must be ruled out before other possibilities are considered. Often medical professionals are unfamiliar with rare diseases since they might see only one or two patients with any one rare disorder in the course of their career. Selection of the appropriate genetic test might not be straightforward considering that there are over nine genetically distinct forms of muscular dystrophy. As a result, long delays in a correct diagnosis are common.

In the case of myotonic dystrophy, diagnosis is complicated even further by the incredible variability of this disease:

• Myotonic dystrophy can take multiple forms that affect a broad spectrum of systems. Clinical presentation of the disease can vary greatly and patients may visit many different specialists for their different symptoms (e.g., an opthalmologist for blurred vision, a gastroenterologist for stomach pain, a cardiologist for an abnormal heartbeat). Physicians might not be aware of their patient's full range of problems and, therefore, may not be able to put the pieces together for an accurate diagnosis.
• The severity of symptoms can vary greatly, even within the same family. Quite often individuals go to their primary care physician with a variety of complaints, most so general that the doctor never suspects any serious problem. As a result, a correct diagnosis may be delayed until the disease has progressed significantly.

Consequently, it is important for patients and their families to be knowledgeable about the disease and their symptoms. Informed patients often know more about the entire spectrum of nyotonic dystrophy manifestations than any one specialist they might visit. Patients must take an active role in the diagnosis and management of their disorder because early diagnosis and monitoring of symptoms can avoid or reduce complications at critical times, including any exposure to anesthesia.

Individuals with nyotonic dystrophy may have concerns about starting a family. Multiple diagnostic options exist for patients who are considering having children (see Family Planning for further information).   

Additional technical information on how physicians diagnose symptoms in the various systems affected by myotonic dystrophy can be downloaded by clicking here.