Myotonic Dystrophy


What is myotonic dystrophy?

Myotonic dystrophy (DM) is an inherited condition that mostly expresses itself in adults (ages 20's-30's) but can also occur at a younger age. Myotonic dystrophy causes a wide range of symptoms which mostly affect muscles. The most common and severe of the symptoms is the results in the breaking down of the muscles causing them to become weak. Some can develop myotonia, which happens when a muscle tightens and cannot relax. Other symptoms result in clouding of the lens in the eye (cataracts), as well as abnormal heartbeats because the electrical signals that control the heart do not work properly. While DM can affect both males and females, men with the condition can have problems with hormone levels that can lead them to lose their hair at a young age (balding), and/or problems having children (infertility). Individuals in a family with DM can each express these symptoms differently.

There are two common types of myotonic dystrophy. Myotonic dystrophy type 1 (DM1) ranges in symptoms as mild as an adult with cataracts and myotonia to something as severe as a baby with muscle weakness and many other complications. The severe form of myotonic dystrophy is also known as congenital DM1. Myotonic dystrophy type 2 (DM2) is only seen in adults and the symptoms are not as severe as in DM1. The muscle weakness seen in DM2 mostly affects the upper extremities, like the neck and arms and can sometimes affect the heart and eyes.

While there is no cure for DM, there are a variety of treatments to help with symptoms. Individuals often have an extensive care team to help with treating the different symptoms. These can include: orthotics to help with walking as a result of muscles weakening. Medications such as mexilitene or carbamazepine can help treat myotonia. An evaluation for hypothyroidism and avoiding cholesterol lowering medication (statins) is important since both cause muscle weakness. Pain and/or fatigue can also be treated with a variety of medications. Seeing a cardiologist can determine the health of the heart as well as whether or not devices like a defibrillator or pacemaker are needed. These devices help with the electrical signals that can sometimes be wrong in DM. Seeing an eye doctor can help check for cataracts, these can be removed if they are causing vision problems. Having physical therapy can help with muscle weakness or problems with walking. If there are problems with breathing or sleep apnea, a specialist in the lungs can determine a treatment. Evaluation and monitoring of diabetes or hyperglycemia by a doctor is also important. Men can receive testosterone hormone replacement therapy if needed. Children with myotonic dystrophy type 1 can be evaluated for low muscle tone, learning and behavioral problems, as well as speech problems. To learn more, visit a reputable site like: Myotonic Dystrophy

SOURCE: Emory University - Department of Human Genetics in collaboration with ThinkGenetic • • DATE UPDATED: 2017-06-20


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