MUTATION ANALYSIS OF THE PHENYLALANINE-HYDROXYLASE GENE USING HETERODUPLEX ANALYSIS WITH SYNTHETIC DNA CONSTRUCTS

Using heteroduplex analysis generated with synthetic PCR-amplifiable D NA we have screened the PKU populations of southwest England and Wales , western Scotland, and southeast and central England for mutations in exons 3, 7 and 12 of the phenylalanine hydroxylase (PAH) gene. The te chnique characterized three mutations in exon 12, two in exon 3 and fi ve in exon 7. Altogether over 370PKU chromosomes were screened. In all geographical regions exon 12 mutations (R408W, IVS12nt1g->a and Y414C ) accounted for about 40% of mutant chromosomes. Exon 3 mutations (pri ncipally I65T) were found on between 9 and 12% of mutant alleles and e xon 7 mutations accounted for a further 5-7%. Heteroduplex analysis is rapid, simple and safe and three constructs covering three exons can identify between 55 and 60% of mutations in various PKU populations of the UK.