Here we reported an anti-SRP-antibody and anti-MDA5-antibody NAM patient who developed severe cardiomyopathy after gaining significant improvement of myopathy and subsequently accepted heart transplantation.<h4>Case presentation</h4>A NAM case with both positive anti-SRP and MDA-5 antibodies who gained significant improvement of the skeletal muscle weakness with immunotherapy, but 3 years later he developed severe dilated cardiomyopathy and at last received heart transplantation. The gene discussed is IFIH1; the disease is cardiomyopathy.