Mitochondrial DNA depletion syndrome causing liver failure.

BACKGROUND: Mitochondrial DNA depletion syndromes are disorders of Mitochondrial DNA maintenance causing varied manifestations, including fulminant liver failure. CASE CHARACTERISTICS: Two infants, presenting with severe fatal hepatopathy. OBSERVATION: Raised serum lactate, positive family history (in first case), and absence of other causes of acute liver failure. OUTCOME: Case 1 with homozygous mutation, c.3286C>T (p.Arg1096Cys) in POLG gene and case 2 with compound heterozygous mutations, novel c.408T>G (p.Tyr136X) and previously reported c.293C>T (p.Pro98Leu), in MPV17 gene. MESSAGE: Mitochondrial DNA depletion syndrome is a rare cause of severe acute liver failure in children.