Den biokemiske defekt ved arvelig tyrosinæmi type 1 (HT- 1) er en mangel på fumarylacetoacetathydrolyase, der er det sidste enzym på tyrosinkatabolismens vej.
The biochemical defect in hereditary tyrosinemia type 1 (HT-1) is a deficiency of fumarylacetoacetate hydrolase, which is the final enzyme of the tyrosine catabolic pathway.