In another clinic, due to lack of cutaneous signs for dermatomyositis, muscular dystrophy was first assumed, and investigation of a tailored genetic panel revealed no pathological mutation in the included genes (ANO5, CAPN3, CAV3, DYSF, FKRP, GAA, MYOT, PYGM, SGCA, SGCB, SGCD, SGCG, TCAP). The gene discussed is PYGM; the disease is dermatomyositis.