Acute Tyrosinemia Type 1 in a 5 Month Old Korean Boy

ABSTRACT

Tyrosinemia type 1 is an autosomal recessive disorder caused by deficiency of the enzyme fumarylacetoacetate hydrolase(FAH). The disease is characterized by hepatic dysfuntion, hepatocellular carcinomas, renal tubular dysfunction, rickets, and neurologic crises. Two forms of the disease, acute and chronic, are thought to be from the residual enzyme activity in the liver. The diagnosis of the tyrosinemia type 1 is suggested by elevated plasma tyrosine, supported by increased urinary succinylacetone, and confirmed by reduced FAH activity in cultured fibroblasts. We had a 5 month old Korean boy with acute tyrosinemia type 1 who presented with recurrent sepsis-like episodes since 2 months of age, progressive liver dysfunction, and rickets. Plasma amino acid analysis showed markedly elevated tyrosine, methionine and urine amino acid analysis was suggestive of Fanconi syndrome showing generalized aminoaciduria. Organic acid analysis by Gas Chromatography/Mass Spectrometry detected large amount of succinylacetone excreted in the urine. Delta-aminolevulinic acid was elevated as well. X-ray findings were characteristics of rickets and abdominal sonogram, CT and MRI revealed cirrhotic liver with varying size of multiple nodules. Liver transplantation was strongly recommended throughout his clinical course but refused by parents, and he died of hepatic failure at the age of 8 months. Autospy was perfomed showing macro and micronodular liver cirrhosis. Kidney was markedly enlarged, however, glomeruli and tubules were relatively unaltered. Mutation analysis is under the study.