Abstract:Hereditary tyrosinemia I (HT I) is an autosomal recessive disease characterized by progressive liver and kidney damage with a high risk of hepatocellular carcinoma. HT I is caused by mutations of the gene encoding fumarylacetoacetate hydrolase (FAH), the last enzyme in the tyrosine catabolic pathway. Several animal models of Fah deficiency have been established, including mouse, rats, rabbits, and pigs, using a recently developed gene-modifying technique. These animal models have become important for liver biology research and are widely used in liver stem cell and hepatic gene therapy studies. Furthermore, Fah mutants can be used as a bioreactor for the expansion of hepatocytes. These chimeric animals have become valuable models for basic research of infectious diseases, metabolism, and gene therapy.Here, we review the progress of animal models of HT I and their applications.