Type I tyrosinemia is a genetic pathology that gives rise to a very serious hepatic metabolic disease, above all because until now it has always been diagnosed after having found the symptoms. It is transmitted in an autosomal recessive manner , by a mutation on chromosome 15 , of the gene for the hydrolysis enzyme fumarylacetoacetate, responsible for liver damage such as hepatocarcinoma, neuronal crises and kidney damage. This pathology is diagnosed correctly in very few cases and only when the symptoms are full-blown, but today thanks to a recent discovery developed by the Meyer Pediatric Hospital and by Perkin Elmer, it will be possible to diagnose type I tyrosinemia at birth, with extensive metabolic screening investigations.
This test for early diagnosis makes preventive care possible in case of a positive result, by detecting the presence of the primary marker for type I tyrosinemia, with a specificity of 100%. Before this test, the risk of death for affected newborns was very high, already around 6-8 months of life.
The introduction in the screening panel of the main metbaolite of the metabolic block, ie succinylacetone , has allowed to obtain a very high specificity, compared to the previous dosage carried out with tyrosine . This innovative test will allow all neonatal metabolic screening laboratories in the world to diagnose type I tyrosinemia in time, especially in countries where the incidence is higher such as Canada.
This demonstrates once again how important newborn screening is, practiced in the first 48 hours of life, and how many lives it can save from irreversible damage such as mental retardation, growth and learning disorders , fulminant tumors and neurological crises. All disorders not easily treatable and not compatible with a normal life.