Mitochondrial diabetes mellitus (MDM) is a rare subtype of diabetes caused by mitochondrial dysfunction, often accompanied by hepatic steatosis. Coenzyme Q10 (CoQ10), a key electron carrier and antioxidant, may improve mitochondrial function and lipid metabolism. This prospective study aims to evaluate the effect of 12-week CoQ10 supplementation (300 mg/day) on liver fat content (assessed by FibroTouch CAP ) in MDM patients with m.3243A\>G mutation. An exploratory case-control design will compare baseline characteristics among MDM patients, type 1 diabetes patients, and healthy controls. This study is the first to explore the link between mitochondrial defects and hepatic fat accumulation specifically in MDM, and to test CoQ10 as a potential therapy, offering new insights for both MDM and MAFLD management.