Tyrosine is an amino acid (a component of protein) found in many food products. The body needs to process tyrosine to utilize it for energy and growth. Tyrosinemia is a rare genetic disorder resulting from a deficiency in the enzyme FAH (Fumarylacetoacetate Hydrolase) required for the processing of tyrosine. As a result, the amino acid accumulates in the liver and causes damage. Tyrosinemia can manifest in the first weeks of life with low weight and signs of liver failure. Other affected children might show progressively worsening signs such as hepatomegaly (enlarged liver), jaundice, vomiting, and diarrhea.
Tyrosinemia is diagnosed through blood tests that can identify signs of liver damage and urine tests that detect breakdown products of the amino acid.
Historically, the treatment strategy involved maintaining a low-protein diet to slow down the accumulation of tyrosine in the body. This posed a significant challenge since finding the delicate balance between excess protein harming the liver and a deficiency of essential protein for body development is crucial. However, since the discovery that the substance known as NTBC halts liver damage, it can now be regularly administered to patients. If the diagnosis is made early and treatment is given promptly, many complications of the disease can be prevented.
Advanced liver failure caused by the disease usually requires liver transplantation, which has positive long-term outcomes.