SNRNP70 and myositis disease: Patients with juvenile-onset SSc more frequently had an overlap syndrome of lcSSc and myositis and showed a higher prevalence of autoantibodies associated with sclerodermatomyositis compared with adult-onset SSc, that is, anti-PM-Scl (14 % vs. 3 %; p < 0.0001) and anti-U1RNP antibodies (16 % vs. 7 % in adults; p < 0.0001) [6].