Myotonic dystrophy is a disease of genetic origin that predominantly affects skeletal muscles.

The age of onset and severity of symptoms are highly variable among patients, even within the same family.

The most characteristic feature is myotonia, which is a difficulty in relaxing the muscles. This problem is usually more evident in the hands and the orbicularis oculi muscles.

Patients often develop other symptoms, including progressive muscle weakness and various non-neurological problems, such as alopecia, cataracts, diabetes mellitus, sleep apnea and heart disease.