Fumarylacetoacetic acid
Fumarylacetoacetic acid is an intermediate in the metabolism of tyrosine. It is formed through the conversion of maleylacetoacetate into fumarylacetoacetate by the enzyme maleylacetoacetate isomerase. Fumarylacetoacetate is hydrolyzed by the enzyme fumarylacetoacetate hydrolase (FAH), producing acetoacetate and fumarate. These compounds may then enter various other metabolic pathways.
Fumarylacetoacetate may accumulate in patients with Tyrosinemia [type I], in which there is a deficiency of the FAH enzyme. In this disease, fumarylacetoacetate and precursors in the catabolism of tyrosine, including maleylacetoacetate, succinylacetone, and homogentisic acid.