DNA-SEQUENCE POLYMORPHISMS IN EXONIC AND INTRONIC REGIONS OF THE HUMAN PHENYLALANINE-HYDROXYLASE GENE AID IN THE IDENTIFICATION OF ALLELES

Five sequence polymorphisms at the phenylalanine hydroxylase (PAH) gen e locus were observed to be in tight association with specific alleles of this locus. Since these polymorphisms can be detected using polyme rase chain reaction (PCR) methodology, application of a combination of these polymorphisms reduces the effort involved in PAH DNA haplotype analysis, which is needed for population genetic analysis or diagnosis of the disease status. In addition our results indicate the evolution of haplotype 3, 4 and 7 PAH alleles from a common ancestor, whereas P AH haplotypes 5, 6, and 11 arose form another common ancestor allele. These data reveal that two of the polymorphisms investigated originate d before the separation of races.