It’s a parent’s worst nightmare– a rare disease that strikes early in life, and without treatment, can cause a patient’s death. Tyrosinemia type 1 (TYR1), is a form of a genetic disorder that prevents the body from breaking down amino acids commonly found in food. Its symptoms usually present themselves during early infancy and include vomiting, bloody stools, fever and diarrhea. TYR1 attacks the brain, the liver and the kidneys.
In the early 1990’s, doctors began using nitisinone to treat TYR1 and the results have been encouraging. Before that, strict dietary management and liver transplants were the only way doctors knew how to improve outcomes for patients. Nitisinone has made a difference in patient outcomes, but it hasn’t been the panacea that parents and doctors have hoped for.
A recent literature review in the Orphanet Journal of Rare Diseases looks at the efficiency of testing newborns for TYR1. There is no debate that identifying TYR1 before symptoms begin is a step towards earlier treatment and better outcomes; however, the authors of the review admit that some question the accuracy of the currently used screening process. The current testing method examines dried blood spots to measure the levels of succinylacetone present.
“Screening tests are not perfect; they give us an indication about a person’s risk but not a definitive answer about whether or not someone truly
has the disease that is being searched for.”
— Sian Taylor-Phillips &
Chris Stinton, REVIEW authors
Taylor-Phillips and Stinton conclude that the use of nitisinone is an effective treatment for TYR1, but acknowledge that the outcome observed may be influenced by biases in the study. The authors believe that a study should include a two-year follow up with participants who tested negative.
Learn more about this study on Biomed Central here.