Liver hepatoblastoma and multiple OXPHOS deficiency in the follow-up of a patient with methylmalonic aciduria

A boy who was diagnosed with methylmalonic aciduria (MMA) at the age of 10 days developed persistent hepatomegaly and raised transaminases from the age of 4 years. He was subsequently diagnosed with Leigh syndrome and required a kidney transplantation for end-stage renal failure. A massive hepatoblastoma led to his death by the age of 11 years. Methylmalonyl-CoA mutase activity was undetectable on both cultured skin fibroblasts and kidney biopsy and multiple respiratory chain deficiency was demonstrated in the kidney. Mitochondrial dysfunction and/or post-transplant immunosuppressive therapy should be considered as a possible cause of liver cancer in this patient.