Our patient presented with symptoms of arthralgia, Raynaud phenomenon, generalized edema, and a positive anti-snRNP antibody at the disease onset, fulfilled the diagnostic criteria of mixed CTD (High titer anti-RNP antibody accompanied by Raynaud phenomenon and 2 or more of the 3 remaining clinical criteria [swollen fingers, synovitis, and myositis]). Here, RNPC3 is linked to synovitis.