Synonyms
Hepatorenal tyrosinemia
Hereditary tyrosinemia type 1
Fumarylacetoacetase deficiency
Congenital tyrosinosis

Disorder Subdivisions
Tyrosinemia type 1, acute form
Tyrosinemia type 1, chronic form

General Discussion
Tyrosinemia type I is a rare genetic metabolic disorder characterized by lack of the enzyme fumarylacetoacetate hydrolase (FAH), which is needed to break down the amino acid tyrosine. Failure to properly break down tyrosine leads to abnormal accumulation of tyrosine and its metabolites in the liver, potentially resulting in severe liver disease. Tyrosine may also accumulate in the kidneys and central nervous system.

Symptoms and physical findings associated with tyrosinemia type I include failure to gain weight and grow at the expected rate (failure to thrive), fever, diarrhea, vomiting, an abnormally enlarged liver (hepatomegaly), and yellowing of the skin and the whites of the eyes (jaundice). Tyrosinemia type I may progress to more serious complications such as severe liver disease. Tyrosinemia type one is inherited as an autosomal recessive trait.