ALLELE FREQUENCY-DISTRIBUTION OF 4 PCR-AMPLIFIED LOCI IN THE SPANISH POPULATION

The allele frequency distributions of four VNTR loci amplified by PCR have been studied in a population of 205 individuals from Spain. The l oci analysed are D1S80 and three STRs: HUMTH01, HUMFES/FPS and HUMACTB F2 (SE33). The former was visualized in Metaphor agarose gels, and the STRs in sequencing polyacrylamide gels under denaturing conditions wh ich could separate alleles with differences of a single base. This is of particular importance in the HUMTH01 locus, a tetrameric STR in whi ch two alleles (9.3 and 10) were detected differing in a single base. Furthermore, HUMACTBP2 has at least 30 alleles, some of which may vary by as little as one base. At this locus a variation in the allele mob ility was observed, depending on the electrophoretic conditions. For t his reason, there should be careful consideration before this marker i s accepted and validated as a common interlaboratory system, This pape r does not include any comparison of the frequencies obtained for this locus with other recent studies. For the rest of the loci, the freque ncies found have been compared with other published population studies ; they show a degree of difference, particularly in the D1S80 locus. F inally, the systems were tested for Hardy-Weinberg equilibrium, and so me statistical parameters of forensic interest were calculated.