ABSTRACT
Background: Due to the large number of PKU-causing mutations in the phenylalanine hydroxylase gene, it may be not possible to detect the mutation. In these cases, segregation analysis of the variable number tandem repeat [VNTR] polymorphic marker associated with this gene is applied in carrier detection of PKU. Considering the population heterogeneity in Iran, we undertook to investigate allelic frequencies of this marker in the province of Yazd [central Iran] until beginning of 2008
Materials and methods: 24 people, including 9 patients and their parents and siblings, were studied. After DNA extraction from their blood, PCR and gel electrophoresis for VNTR containing fragment was carried out
Results: Totally, 6 VNTR alleles were identified. Only 4 of them were present in mutant chromosomes. The distribution of PKU alleles in chromosomes was as follows: 5.5% VNTR3, 11.0% VNTR7, 78.0% VNTR8 and 5.5% VNTR12. In non-PKU chromosomes, alleles were distributed as follows: 20.0% VNTR3, 20.0% VNTR7, 33.0% VNTR8, 13.0% VNTR9, 7.0% VNTR11 and 7.0% VNTR12. Polymorphic information content [PIC] of this marker was calculated at 63%
Conclusion: This PIC indicates that it is a suitable marker for carrier detection of PKU in the first degree relatives of population under study