Abstract
Tyrosinemia type 1 is a rare metabolic disease with autosomal recessive inheritance caused by biallelic mutations in the FAH gene, leading to impaired activity of fumarylacetoacetate hydrolase, a key enzyme in tyrosine metabo-lism. In children with TYR 1, an activation of alternative metabolic pathway leads to an overproduction of toxic metabolites, mainly succinylacetone and fumarylacetoacetate, which damage hepatocytes and renal tubular cells.
Clinically, TYR 1 presents with acute progression to liver and renal failure at an early age or chronically with the development of liver fibrosis, cirrhosis, rickets and hepatocellular carcinoma, manifestations of porhyria crisis are also common. Biochemical diagnosis is based on evidence of increased levels of succinylacetone in the blood and urine, accompanied by an elevation of tyrosine and rising level of alpha-fetoprotein.
The diagnosis must be confirmed at the molecular level. The treatment is based on an administration of nitisinone, which blocks the production of toxic metabolites in combination with a low-protein diet supplemented with a mixture of essential amino acids without tyrosine and phenylalanine.
If conservative therapy does not prevent the progression of liver failure or the development of hepatocellular carcinoma, liver transplantation is indicated. We present the clinical course of the disease in a 10-month-old boy with TYR1, manifesting with hepatopathy, melena, and hepatocellular carcinoma.
In addition to nitisinone and diet, chemoembolization of the supplying hepatic artery in the area of the fastest-growing carcinoma was necessary, which enabled us to gain time to prepare liver transplantation. After a successful transplant, the boy is in a good clinical condition.