INVESTIGATION OF THE CORRELATION BETWEEN VNTR AND PAH GENE MUTATIONS IN PKU PATIENTS IN GUILAN PROVINCE, IRAN

VNTR alleles in the phenylalanine hydroxylase (PAH) gene are used for carrier detection and prenatal diagnosis in phenylketonuria families. The aim of this study was to investigate linkage between VNTR alleles and the PAH gene mutations in PKU patients in Guilan province, Iran.

In this descriptive cross-sectional study, 19 unrelated PKU patients from 17 Shahrivar children hospital in Rasht were enrolled. Genomic DNA was extracted from blood samples of PKU patients. Amplification of gene fragments was carried out by PCR method and underwent direct sequencing.

Our analysis showed that PKU patients in Guilan province had VNTR3/VNTR3, VNTR3/VNTR7, ND/VNTR7, VNTR7/VNTR7, and VNTR8/VNTR8 genotypes in PAH gene. The frequencies of VNTR3, VNTR7, and VNTR8 alleles were 21.05%, 28.94%, and 47.4%, respectively. Length of one allele was not determined (ND) by frequency 0.03%. The linkage between was observed in some mutations of PAH gene such as R400K, R261X, R261Q, IVS4+5G>T و and IVS10-11G>A with VNTR allelels PKU patients.

VNTR3, VNTR7, and VNTR8 alleles can be considered as useful marker in determining PKU carriers in Guilan. Furthermore, Genetic heterogeneity and geographic variation may be the cause of correlation of different mutations with VNTR alleles in PAH gene in Guilan province.