Tyrosinemia Type I

Tyrosinemia Type I (also called hepatorenal tyrosinemia) is the most severe form of tyrosinemia, a group of inherited metabolic disorders affecting the breakdown of the amino acid tyrosine. When the enzyme fumarylacetoacetate hydrolase (FAH) is deficient, toxic metabolites accumulate in the liver, kidneys, and nervous system, causing progressive damage if untreated.

The acute form presents in the first months of life with severe liver failure, coagulopathy (bleeding problems), and a distinctive "cabbage-like" odor. Without treatment, death from liver failure typically occurs within the first year. The chronic form presents later with milder liver disease, rickets-like bone changes due to kidney involvement (renal tubular dysfunction), and episodes of painful peripheral neuropathy.

Prior to modern treatment, hepatocellular carcinoma (liver cancer) developed in the majority of patients who survived early childhood, often appearing before age 5. The accumulated toxic metabolites are directly carcinogenic to liver cells. Even with dietary management alone, the risk of liver cancer remained extremely high.

Tyrosinemia Type I is caused by mutations in the FAH gene and is inherited in an autosomal recessive pattern. It is particularly common in the Saguenay-Lac-Saint-Jean region of Quebec, where the carrier frequency is approximately 1 in 20. Since 1992, treatment with nitisinone (NTBC) has transformed the prognosis—it blocks tyrosine degradation upstream of the toxic metabolites, preventing liver and kidney damage when started early. Combined with dietary protein restriction, most children now develop normally and avoid liver cancer.

NutraHacker examines the following gene related to Tyrosinemia Type I:

• FAH

For more information about your own genetic profile as related to Tyrosinemia Type I, please check out our NutraHacker Carrier Status and Drug Response Report.

Or to get going without any further delay, upload raw DNA data and find out more about your carrier status today.