Thirty-one unrelated phenylketonuria patients from the Moscow region were screened for mutations in the phenylalanine hydroxylase gene at the following codons: 408, 158, 261 and IVS-12. For detection of point mutations, polymerase chain reaction amplification was applied with allele-specific oligonucleotide hybridization. The following mutation frequencies were determined: codon 408 – 56.4%; codon 158 – 8.1%; codon 261 – 3.2%, and IVS-12 – 16%.

The investigation of a DNA-amplified fragment of a phenylketonuria (PKU) patient by sequencing reveals a novel mutation in the PAH gene. This mutation represents the deletion of a single base (guanine) localized at the intron 11/exon 12 junction. This newly described mutation may be a frameshift or a splicing mutation. The identified mutation expresses phenotypically as the severe form of PKU.

No abstract