Here, we present the case of a 42-year-old woman who developed DM, characterized by proximal muscle weakness in the upper and lower extremities, dysphagia, heliotrope rash, periungual erythema, erythematous skin lesions on the neck and arms, elevated serum aldolase and creatine phosphokinase (CPK) levels, and positive anti-melanoma differentiation-associated gene 5 (MDA5) antibodies. Here, PIK3C2A is linked to dermatomyositis.