Longitudinal Study of Mitochondrial Hepatopathies

This study will be conducted as part of the NIH-supported Childhood Liver Disease Research and Education Network (ChiLDREN). ChiLDREN is investigating rare cholestatic liver diseases of childhood: alpha-1 antitrypsin deficiency (A1AT), Alagille's Syndrome (AGS), progressive familial intrahepatic cholestasis (PFIC), bile acid synthesis defects and mitochondrial hepatopathies (all previously studied by the Cholestatic Liver Disease Consortium \[CLiC\]); biliary atresia (previously studied by the Biliary Atresia Research Consortium \[BARC\]); neonatal hepatitis; and cystic fibrosis liver disease, which is studied by a new branch of ChiLDREN known as the Cystic Fibrosis Liver Disease (CFLD) Network. In this protocol, mitochondrial hepatopathies in children and young adults will be investigated. The focus will be on respiratory chain defects (RC) and defects of fatty acid oxidation (FAO). There is little known about the full spectrum of severity and long-term natural history of mitochondrial hepatopathies. Moreover, these disorders have not been subject to prospective, rigorous clinicopathological scrutiny.