[Frequencies of 6 known mutations in phenylalanine hydroxylase gene and their application in prenatal gene diagnosis].

The known mutant alleles of human phenylalanine hydroxylase gene were analyzed in 25 phenylketonuria (PKU) families from North China by polymerase chain reaction combined with allele-specific oligonucleotide dot hybridization techniques. The results showed that the six mutation accounted for 62% of all PKU genes. The three most frequent mutations were Arg243-->Gln in exon 7, Arg413-->Pro in exon 12 and Tyr204-->Cys in exon 6. They accounted for 24%, 18% and 16% respectively of all PKU alleles. The frequencies of Arg111-->Ter mutation in exon 3, Tyr356-->Ter mutation in exon 11 and Trp326-->Ter mutation in exon 10 were somewhat lower in North China. They accounted for 4% of all PKU alleles. Among these 25 PKU families, prenatal gene diagnosis was possible in 10 families. In 11 families, 50% exclusive diagnosis was possible. Prenatal gene diagnosis was performed and confirmed in 2 families.