The precise cause of mixed connective tissue disease isn't known.

Mixed connective tissue disease is an autoimmune disorder. In autoimmune disorders, your immune system — responsible for fighting off disease — mistakenly attacks healthy cells.

In connective tissue diseases, your immune system attacks the fibers that provide the framework and support for your body. Researchers are working to identify proteins produced by the immune system that might cause mixed connective tissue disease.

Some people with mixed connective tissue disease have a family history of the condition. But the role of genetics in causing the disease remains unclear.

April 03, 2015