In the context of physiology, tyrosinosis is a metabolic disorder resulting from the deficiency of a specific enzyme. To determine which enzyme deficiency causes tyrosinosis, we must understand the role of enzymes in the metabolic pathway of tyrosine. Tyrosine is metabolized through a series of enzymatic steps, and any disruption can lead to metabolic disorders.
Tyrosinosis is caused by a deficiency in the enzyme fumarylacetoacetate hydrolase. This enzyme is crucial in the final step of the tyrosine catabolic pathway, where it catalyzes the hydrolysis of fumarylacetoacetate into fumarate and acetoacetate. When this enzyme is deficient, fumarylacetoacetate accumulates, causing tyrosinosis.
In contrast, other enzymes mentioned, such as p-hydroxy phenylpyruvate dehydrogenase or tyrosine transaminase, are involved in earlier steps of the tyrosine catabolism. Their deficiencies are linked to different metabolic disorders, not specifically tyrosinosis.