Gene FAH
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Also known as
fumarylacetoacetate hydrolase, fumarylacetoacetaseOverview
FAH (Fumarylacetoacetate Hydrolase) encodes the final enzyme in the tyrosine degradation pathway, converting fumarylacetoacetate to fumarate and acetoacetate. This enzyme is essential for the complete breakdown of the amino acid tyrosine and prevents accumulation of toxic intermediates in the pathway.Deficiency of FAH causes hereditary tyrosinemia type 1 (HT1), the most severe form of tyrosinemia. Without treatment, HT1 leads to severe liver disease, renal dysfunction, neurological crises, and hepatocellular carcinoma in early childhood. The drug nitisinone (NTBC) blocks an earlier step in the pathway, preventing toxic intermediate accumulation, and combined with dietary tyrosine and phenylalanine restriction has transformed outcomes for affected individuals.
Understanding your FAH genetic status is critical for newborn screening and carrier identification. Early diagnosis and treatment initiation can prevent the severe complications of HT1 and enable normal development and lifespan.