Background: Hereditary Tyrosinemia I (HT1) is an inborn error of tyrosine catabolism; an
autosomal recessive disorder caused by defective activity of fumarylacetoacetate hydrolase (FAH) enzyme, is
characterized by progressive liver disease, renal tubular dysfunction, and porphyria-like crises.
Succinylacetone (SA); a compound derived from the tyrosine catabolic intermediate fumarylacetoacetate has
been demonstrated to be a mitochondrial toxin. Symptoms may start during the first few months (acute type); in
second half of the first year (subacute type) or in the following years up to adulthood (chronic type). All patients
stand a high risk of developing hepatocellular carcinoma (HCC) secondary to cirrhosis. Diagnostic methods:
Elevated levels of SA, α fetoprotein and plasma levels of tyrosine, phenylalanine and methionine, Newborn
screening and prenatal diagnosis are available in many countries. Management and treatment: A dramatic
improvement in prognosis following treatment with Nitis