Mixed connective tissue disease

Overview
Mixed connective tissue disease (MCTD) or Sharp's syndrome is a human autoimmune disease in which the immune system attacks the body. MCTD combines features of polymyositis, systemic lupus erythematosus, and systemic scleroderma and is thus considered an overlap syndrome. MCTD commonly causes joint pain/swelling, Raynaud phenomenon, muscle inflammation, and scarring of the skin of the hand. It does not typically cause kidney disease or seizures. Distinguishing laboratory characteristics are a positive, speckled anti-nuclear antibody and an anti-U1-RNP antibody.