To the Editor:Mitochondrial encephalomyopathy with lactate acidosis and stroke-like episodes (MELAS) is one of the most common multisystem mitochondrial disorders with broad clinical manifestations.[1] It is usually caused by point mutations in the mitochondrial MT-TL1 gene,which accounts for approximately 80％ of mutations in individuals with MELAS syndrome.[2] Pathogenic mitochondrial DNA (mtDNA) mutations were first described in 1988[3] and m.14487T＞C is a known pathogenic mtDNA mutation,[4] which has been reported in patients with Leigh syndrome,optic neuropathy,ptosis,dystonia,and encephalomyopathy.We herein report a patient with late-onset MELAS syndrome with the m.14487T＞C mutation for the first time.