Tyrosinemia, Type I (TYR-I)


Tyrosinemia, Type I (TYR-I) is an inherited condition in which the body is unable to break down certain building blocks of proteins, known as amino acids. TYR-I is considered an amino acid condition because people with this condition are unable to break down the amino acid tyrosine. If untreated, tyrosine and its byproducts build up in tissues and organs, which leads to serious medical problems that can lead to liver and kidney failure, problems affecting the nervous system, and an increased risk of liver cancer. Detecting the condition early and beginning treatment can often prevent the severe outcomes of TYR I.

This condition is also known as: hereditary tyrosinemia, hepatorenal tyrosinemia, fumarylacetoacetase deficiency, fumarylacetoacetate hydrolase deficiency, FAH deficiency, tyrosinosis, hypertyrosinemia.

For more information about Tyrosinemia, Type I, go to Screening, Technology, and Research in Genetics (STAR-G): Tyrosinemia, Type I and Baby's First Test: Tyrosinemia, Type I. Please see Medically Prescribed Formula for information about medically prescribed formula and pharmacologic interventions for inborn errors of metabolism. Visit Board Certified Metabolic Providers (PDF: 2 pages/204KB) for a listing of medical specialists and clinic contact information.