Tyrosinemia
Grace E. Kim, MD
Key Facts
Terminology
Synonym: Tyrosinemia, type I
Etiology/Pathogenesis
Mutations in fumarylacetoacetate hydrolase gene on 15q23-q25
Fumarylacetoacetate hydroxylase deficiency
Clinical Issues
Elevated plasma and urine succinylacetone
Many patients have renal tubular dysfunction
Liver transplantation is treatment of choice for medical treatment failures
15-37% risk of developing hepatocellular carcinoma
Microscopic Pathology
Variable fatty change and cholestasis
Pericellular and periportal fibrosis to cirrhosis
 This micronodular cirrhotic liver demonstrates patchy areas of large droplet fatty change in some nodules. |
 A dysplastic nodule  displays both small cell change and widened plate architecture. Note the adjacent normal liver  . (Courtesy M. J. Finegold, MD.) |
TERMINOLOGY
Abbreviations
Fumarylacetoacetate hydroxylase (FAH) deficiency
Synonyms
Tyrosinemia, type I
Hereditary tyrosinemia
Hepatorenal tyrosinemia
Definitions
Inborn error of metabolism
Autosomal recessive inheritance
Tyrosine catabolism pathway
Deficiency of fumarylacetoacetate hydroxylase
Results in cirrhosis and hepatocellular carcinoma early in life
ETIOLOGY/PATHOGENESIS
