What is the main cause of Tyrosinemia?

Tyrosinemia is primarily caused by a deficiency in the enzyme fumarylacetoacetase (FAA), which is crucial for the proper breakdown of the amino acid tyrosine. When this enzyme is deficient, tyrosine and its metabolites accumulate in the body, leading to a range of health issues, including liver dysfunction, renal tubular acidosis, and potential neurological complications. This condition is part of a metabolic pathway where tyrosine is broken down into fumarate and acetoacetate, and the lack of FAA disrupts this process, resulting in the clinical manifestations associated with Tyrosinemia.

The other options refer to deficiencies that are associated with different metabolic disorders. For example, a deficiency of phenylalanine hydroxylase is linked to Phenylketonuria (PKU), which involves the inability to convert phenylalanine to tyrosine. Alpha-glucosidase deficiency is associated with Pompe disease, a glycogen storage disorder, and glycogen branching enzyme deficiency causes Andersen disease. Thus, these conditions represent entirely different biochemical pathways and clinical presentations, confirming that the correct option is indeed the deficiency of fumarylacetoacetase as the main cause of Tyrosinemia.