Molecular genetic analysis of the VNTR alleles at the phenylalanine hydroxylase (PAH)
gene was carried out in seven Volga-Ural ethnic groups (Bashkirs, Tatars, Chuvashes,
Maris, Mordovians, Udmurts, and Komis). The PCR fragments revealed included alleles
of 380, 440, 470, 500, 530, 560, and 650 bp, containing 3, 5, 6, 7, 8, 9, and 12 repeat
copies, respectively. Substantial heterogeneity of the populations in respect to the
distribution and frequency of the VNTR alleles and genotypes was demonstrated. The
indices of observed and theoretical heterozygosity of the PAH VNTR alleles were calculated.
The mean heterozygosity index was 70.02%. This high index value along with the established
differentiation of the populations in respect to the frequency distribution of the
VNTR alleles and PAH genotypes permitted the conclusion that the given polymorphic
locus can serve as a highly informative marker for examination of the genetic structure
of the Volga-Ural populations.