Acute infantile liver failure due to synthesis defect of mtDNA-encoded proteins is a rare and potentially fatal condition that affects infants. It is caused by a defect in the synthesis of proteins encoded by mitochondrial DNA (mtDNA). This defect leads to a decrease in the production of essential proteins, resulting in liver failure. Symptoms of this condition include jaundice, poor feeding, vomiting, and lethargy. Treatment typically involves supportive care, such as providing nutrition and fluids, and may include liver transplantation.