Abstract
BACKGROUND: Cardiomyopathy due to SLC25A20 mutations typically manifests in the neonatal period, characterized by rapid progression and high mortality. CASE SUMMARY: A 62-year-old man presented with late-onset dilated cardiomyopathy (DCM) associated with a heterozygous SLC25A20 c.199-10T>G mutation. Comprehensive evaluation, including biochemical testing, echocardiography, cardiac magnetic resonance imaging, and invasive coronary angiography, ruled out other potential etiologies. The patient received guideline-directed medical therapy in conjunction with cardiac resynchronization therapy, leading to significant clinical and functional improvement. DISCUSSION: To our knowledge, this represents the oldest reported case of SLC25A20-related DCM. This case highlights the clinical presentation, multimodal imaging findings, and therapeutic response in late-onset SLC25A20-related cardiomyopathy. TAKE-HOME MESSAGES: Although rare, SLC25A20 mutations can contribute to late-onset DCM. Optimized heart failure management, including multimodal therapeutic strategies, may improve cardiac function in patients with SLC25A20-related DCM.