Mitochondrial hepatopathies.

ABSTRACT

Hepatocyte mitochondrion functions as a cause and as a target of liver injury. Since the mitochondria are under dual control of nuclear DNA and mitochondrial DNA (mtDNA), mutations in genes of both classes have been associated with inherited mitochondrial hepatopathies. Point mutations, deletions, insertions, rearrangements, DNA depletion--all have been identified. Many factors influence the prevalence of mitochondrial disorders, including the mutations rate, inheritance pattern, population structure, and the genetic background. In primary disorders, mitochondrial defect is the primary cause of liver disease often producing fatal hepatic failure in infancy or childhood. In secondary disorders, insult to mitochondria is caused by either a gene defect that affects non-mitochondrial proteins or by an exogenous injury to mitochondria. Diagnosis should be suspected in cases of liver disease with neuromuscular symptoms, multisystem involvement that cannot be explained by a single pathology or rapidly progressive liver failure in early childhood. Laboratory findings in the blood and urine show an altered redox status. Various antioxidants, vitamins, cofactors, and electron acceptors have been for proposed but none is effective. Presence of neuromuscular or extraintestinal involvement in primary disorder precludes the use of liver transplantation.