[Juvenile Sharp syndrome (mixed connective tissue disease)].

Five children with Sharp syndrome are described presenting a non-erosive polyarthritis, hand and finger swelling, Raynaud phenomenon, myositis, dermatomyositis or SLE-like rash. Characteristic laboratory findings are, apart from elevated sedimentation rate, anemia and leucopenia, high titer IgM rheumatoid factors and antinuclear antibodies (ANA). The latter show speckled pattern, contain IgG, bind complement components and are directed against ribonuclease-sensitive nuclear antigens. All patients have antibodies against the so-called extractable nuclear antigens (Anti-ENA) and antibodies against ribonucleoproteins (Anti-RNP). Since children with Sharp syndrome rarely show renal or cerebral involvement, the prognosis seems to be fairly good.