[Analysis of the A/C polymorphic site within the phenylalanine hydroxylase gene]

An A/C polymorphism was identified at nucleotide-11 from the acceptor site of IVS3 of the phenylalanine hydroxylase gene. This polymorphism can be detected easily by means of single strand conformation polymorphism analysis. The frequency for the majior allele (A) was 0.656 and 0.344 for the minor allele (C) with the PIC being 0.351 in Chinese population. There was no linkage disequilibrium between this site and the STR polymorphic site located upstream within the same intron of the gene. The ejjicincy of prenatal gene diagnosis fro PKU was estimated to be 78.1% by haplotype linkage analysis using these two polymorphic sits.