One breastfed infant, born to the woman with m.4300A>G variant, who experienced gestational severe hypertriglyceridemia, had prolonged jaundice with mildly elevated levels of liver enzymes (elevated alanine transaminase and gamma-glutamyl transferase with conjugated hyperbilirubinemia), an enlarged hyperechogenic liver (indicative of hepatic steatosis) on ultrasound scan and hyperlipidaemia (serum triglyceride 7.5 mmol/L; normal < 1.15 mmol/L). The gene discussed is GPT; the disease is fatty liver disease.