Most often, HT-1 is diagnosed at birth through new born screening. If not diagnosed at birth, signs often develop during the first few months of life.
Babies may show visible signs of the condition within the first months of life, however, symptoms of the disease may not be evident to the parents. Failure to thrive, an enlarged liver, poor weight gain, abdominal pain, vomiting and diarrhea are possible signs of this disorder.
Children with tyrosinemia type 1 have an increased risk of developing liver problems. Signs of liver distress and failure include gastrointestinal bleeding and jaundice, a yellowing of the whites of the eyes as well as the skin. The liver failure later leads to a characteristic odor of 'boiled cabbage' or 'rotten mushrooms' from the child's skin or urine.
When the body cannot break down tyrosine, an amino acid that comes from food, high levels of it build up in the blood and form a toxic substance known as succinylacetone. Elevated levels of succinylacetone are always present in children with tyrosinemia type 1, and can be measured in both the blood and urine. During treatment, succinylacetone quickly disappears.
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).