Tyrosinemia is an extremely rare but treatable hereditary disorder that must be inherited from both parents. Boys and girls are affected in equal numbers. When a child has tyrosinemia, their bodies lack the enzymes needed to break down tyrosine.
Tyrosine comes from food. It is one of the 20 amino acids, the building blocks of protein. When the body cannot break down tyrosine, high levels build up in the blood and form a toxic substance (knows as succinylacetone) in the liver, kidneys, and central nervous system. This means that if tyrosinemia isn't treated, it may cause liver and kidney damage and brain-related problems, such as problems with learning.
There are three types of tyrosinemia. The type a child has depends on which enzyme they are lacking. Children with tyrosinemia type 1 (HT-1) are deficient in an enzyme called fumarylacetoacetate hydrolase. If not recognized and treated right away, the condition could be fatal for a child at an early age. However, with treatment, tyrosine levels in the blood can be managed.
Orfadin is a synthetic reversible inhibitor of 4-hydroxyphenylpyruvate dioxygenase indicated for use as an adjunct to dietary restriction of tyrosine and phenylalanine in the treatment of hereditary tyrosinemia type 1 (HT-1).