Longitudinal Study of Mitochondrial Hepatopathies

The specific aims of this study are (1) to determine the clinical phenotypes and natural history of hepatic RC and FAO disorders, (2) to determine the correlation between genotype and phenotype, (3) to determine if circulating biomarkers reflect diagnosis and predict liver disease progression and survival with the native liver, (4) to determine the clinical outcome of these disorders following liver transplantation, and (5) to develop a repository of serum, plasma, urine, tissue and DNA specimens that will be used in ancillary studies. To accomplish these aims, the ChiLDReN investigators at clinical sites (currently 9 sites) will prospectively collect defined data and specimens in a uniform fashion at fixed intervals in a relatively large number of subjects. Clinical information collected from subjects and their parents will enhance the potential for meaningful research in these disorders. A biobank of previously collected subject specimens and DNA samples will be established for use in ancillary studies to be performed in addition to this study.

Subjects in Group 1 (Mitochondrial Hepatopathy group) must meet all of the following inclusion criteria: 1. Children and young adults with suspected or documented hepatic RC defector FAO defect from birth to 18 years old (through 18 years). 2. Both sexes, all races and ethnic groups. 3. Participants must meet one of the following sets of criteria (A or B): A. Potential subjects presenting with acute or chronic liver disease or acute liver failure but who have not had a liver transplant must meet one of Clinical Criteria 1 and one of Clinical Criteria 2 listed below: 1. Clinical Criteria 1 (any one of the following) * 1.Acute liver failure, defined as severe liver dysfunction and either 1) INR \>1.5 or prothrombin time \> 15 seconds with encephalopathy or 2) INR \> 2.0 or prothrombin time \> 20 seconds with or without encephalopathy; occurring within 8 weeks of onset of illness; with no known underlying chronic liver disease, or * 2.Acute liver disease defined as elevated AST or ALT \>1.25 ULN and CK \2.0 mg/dl and \>20% of total bilirubin, or * 3.Chronic liver disease defined as: * elevated ALT or AST (\>1.25 ULN) for \> 6 months, or * conjugated hyperbilirubinemia (conjugated \[direct\] \> 2.0 mg/dl and \> 20% of total bilirubin) for \> 6 months or * clinical stigmata of chronic liver disease, including chronic hepatomegaly, clinical findings or complications of cirrhosis or portal hypertension, impaired liver synthetic function, intractable pruritus explainable only by liver disease or end-stage liver disease, or * abnormal liver histology including hepatic fibrosis or cirrhosis, microvesicular steatosis, canalicular cholestasis, ballooned granular red hepatocytes (AKA oncocytes), intralobular collapse/regeneration And 2. Clinical Criteria 2 (any one of the following): * 1.Prior history of extra-hepatic organ involvement accompanied by any one or more of the signs and symptoms associated with mitochondrial dysfunction (e.g. hypotonia, neuro-developmental delay, seizure disorder requiring treatment with valproic acid, nystagmus, cardiomyopathy, renal tubulopathy, bone marrow failure, myopathy, hearing loss), or * 2.Lactic acidosis (arterial blood or free-flowing venous blood level \>2.5 mmol/L or \>22.5 mg/dl at any age and increased lactate:pyruvate ratio \[\>25.0\]) or * 3.Hypoglycemia (blood glucose \22.5 mg/dl at any age and increased lactate:pyruvate ratio \[\>25.0\]), OR * A prior history of hypoglycemia (blood glucose \