Sharp et al first described mixed connective tissue disease (MCTD)in 1972 as a distinct entity of connective tissue disease (1). MCTDis a disease entity characterized by overlap symptoms of systemic lupus erythematosus (SLE), systemic sclerosis (SSc) and polymyositis/dermatomyositis (PM/DM), as well as by the presence of antibody to U1RNRHowever, it has been suggested that rather than being reg...