Examples of atrophying muscle diseases include muscular dystrophy, myotonia congenita, and myotonic dystrophy. Two types of myotonia congenita exist, an autosomal dominant form and an autosomal recessive form. Electromyography may be used to distinguish between paramyotonia congenita and myotonia congenita. Of note, myotonia congenita has no association with malignant hyperthermia (MH). In northern Scandinavia, the prevalence of myotonia congenita has been estimated at 1&colon;10,000. Symptoms of myotonia (documented in myotonia congenita) are more frequently experienced in women during pregnancy. This muscle stiffness cannot be walked off, in contrast to myotonia congenita. Although myotonia in itself is not normally associated with pain, cramps or myalgia may develop. Phenotypes are quite variable, and manifestations can include weakness, abnormal gait, myotonia, cramps, and scoliosis. For other patients, exercise consistently induces symptoms of myotonia or weakness. During the 1970s several murine models of myotonia appeared. Avoidance of myotonia triggering events is also an effective method of mytonia prevention. In order to study myotonia in goats, researchers relied on the isolation of RNA protein. Myotonia congenita is estimated to affect 1 in 100,000 people worldwide.