Prenatal Diagnosis of Hereditary Tyrosinemia by Determination of Fumarylacetoacetase in Cultured Amniotic Fluid Cells

Abstract

Fumarylacetoacetase was assayed in cultured amniotic fluid cells from 4 pregnancies at risk for hereditary tyrosinemia and in 11 controls. The enzyme activity was normal in 3 of the pregnancies at risk for tyrosinemia and healthy children were born. In the 4th case the enzyme activity was deficient, indicating an affected fetus. As the pregnancy was very advanced it was continued, and the child has tyrosinemia. One parent in 1 of the 4 families is a compound heterozygote for the tyrosinemia gene and the recently reported pseudodeficiency gene for fumarylacetoacetase. This has important consequences for prenatal diagnosis in this family.