Tyrosinemia type I--diagnostic issues and prenatal diagnosis.

A fifteen-month-old boy, born to consanguineously married couple, presented with asymptomatic hepatomegaly. Investigations revealed mildly deranged liver functions, necroinflammatory changes and cirrhosis on liver biopsy, a markedly raised alpha feto protein and tyrosine levels in plasma and a generalized aminoaciduria. His diagnosis of hereditary tyrosinemia was established on findings of raised serum and urine succinylacetone and a deficient activity of fumaryl acetoacetate hydroxylase enzyme. Prenatal diagnosis of hereditary tyrosinemia was performed in a subsequent pregnancy in this family from India.