This information is provided by the National Institutes of Health (NIH) Genetic and Rare Diseases Information Center (GARD).
Rippling muscle disease (RMD) is a rare condition that primarily affects the muscles. It belongs to a group of conditions known as caveolinopathies. Signs and symptoms of the condition generally begin during late childhood or adolescence, although the age of onset can vary widely. It is characterized by signs of increased muscle irritability, including percussion-induced rapid contractions (repetitive tensing of the muscle), percussion-induced muscle mounding (“bunching up” of the muscle), and/or visible rippling of the muscles. Fatigue, cramps, and/or muscle stiffness are common, especially after strenuous activity or exposure to cold temperatures. Some affected people may also have hypertrophy (overgrowth) of some muscles and an unusual gait. Treatment is said to be supportive and based on the signs and symptoms present in each person.
Rippling muscle disease can be caused by changes (mutations) in the CAV3 gene. Inheritance is usually autosomal dominant, but can be autosomal recessive. In addition to RMD, CAV3 gene mutations can cause features of the other caveolinopathies, even within the same family. The other caveolinopathies are: limb-girdle muscular dystrophy 1C, isolated hyperCKemia, CAV3-related distal myopathy, and hypertrophic cardiomyopathy.
There have also been reported cases of an acquired, autoimmune form of RMD that occurs concurrently with myasthenia gravis. In this form, there is no family history of RMD and CAV3 testing is negative.
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