The MOST appropriate method to confirm the diagnosis of tyrosinemia type 1is by elevated level of

(D). The presence of elevated levels of succinylacetone in serum and urine is diagnostic for tyrosinemia type i. Increased levels of a-fetoprotein are present in the cord blood of affected infants, indicating intrauterine liver damage. Plasma tyrosine levels are usually elevated at diagnosis but this is a nonspecific finding and is dependent on dietary intake. Plasma levels of other amino acids, particularly methionine, may also be elevated in patients with liver damage. The urinary level of 5- aminolevulinic acid is elevated because of inhibition of 5-aminolevulinic hydratase by succinylacetone