Mixed Connective Tissue Disease (cont.)

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What is mixed connective tissue disease?

Mixed connective tissue disease, as first described in 1972, is "classically" considered as an "overlap" of three diseases, systemic lupus erythematosus, scleroderma, and polymyositis. Patients with this pattern illness have features of each of these three diseases. They also typically have very high quantities of antinuclear antibodies (ANAs) and antibodies to ribonucleoprotein (anti-RNP) detectable in their blood. The symptoms of many of these patients eventually evolve to become dominated by features of one of three component illnesses, most commonly scleroderma. Mixed connective tissue disease is often abbreviated MCTD.

It is now known that overlap syndromes can occur that involve any combination of the connective tissue diseases. Therefore, for example, patients can have a combination of rheumatoid arthritis and systemic lupus erythematosus (hence, the coined name "rhupus").

What are causes and risk factors for mixed connective tissue disease?

The most significant causes and risk factors for developing mixed connective tissue disease are certain gene patterns that are inherited from ancestors. There is no known environmental toxin that has been shown to cause mixed connective tissue disease.

What are signs and symptoms of mixed connective tissue disease?

The signs and symptoms of mixed connective tissue disease vary greatly from one individual affected to another. If polymyositis is the dominant feature, muscle weakness is prominent. If systemic lupus erythematosus prevails, there may be chest pain with breathing, kidney disease, and/or arthritis of the joints. If scleroderma symptoms dominate, there can be diffuse swelling and thickening of the fingers and feet with bluish discoloration of the fingers after cold exposure (Raynaud's phenomenon).

Medically Reviewed by a Doctor on 2/18/2015