Genetic variation of 23 STR loci in a Northeast Colombian population (department of Santander)

The most efficient markers to solve filiation cases are the STRs, including complex cases that require the analysis of a greater number of markers. In this study samples from 123 unrelated individuals from the department of Santander (northeast Colombia) were typed for 23 autosomal STRs included in VeriFiler express kit (Thermo Fisher Scientific),and their allele frequencies and parameters of forensic relevance were determined. Results demonstrate independence within and between the loci analyzed, and the accumulate power of exclusion for the full set of markers was high (99.9996%), as well as the match probability, which was 1 in 8.77E + 29. Therefore, this northeast Colombian population database can be used in forensic to estimate the frequency of the genetic profile using of a multiple locus including in this DNA kit.     

Genetic STRs variation in a large population from Tuscany (Italy)

Allele frequencies for 17 STRs, together with some parameters of forensic interest, were estimated in a sample of 835 unrelated individuals born in Tuscany, an Italian region. These data were compared with Italian, Chinese, Kosovo Albanian, Romanian and Tunisian populations, strongly represented in this area. No significant differences in single loci were detected, except for Chinese in comparison with all the other populations.     

Genetic polymorphism of 14 non-CODIS STR loci for forensic use in southeast China population

We investigated 14 polymorphic STR loci (D1S2142, D2S1360, D3S1545, D7S1517, D10S2325, D12S391, D13S1492, D14S306, D15S659, D16S3253, D18S1270, D19S253, D20S470, D21S1437) which are not included in the standard sets of forensic loci (CODIS) in a sample of 216 unrelated healthy southeast Chinese individuals. The studied loci were highly informative and did not show departures from Hardy-Weinberg equilibrium. The accumulated powers of discrimination and power of exclusion for the 14 loci were 99.9999999999 and 99.999998%, respectively. No linkage was observed between the 14 loci and the traditional set of STR markers included in commercially available kits (the AmpFLSTR IdentifilerTM 15 System loci). We thus considered the studied 14 STRs are informative and when necessary, can be used as the candidate genetic markers in the study and application in genetics and forensic practice.     

Sequence analysis of a new short tandem repeat locus D17S2266E located in the human growth hormone gene cluster HumGH@

D17S2266E is a new, variable genetic marker exhibiting polymorphism of the number of repeats of four- and two-nucleotide motifs. This study, carried out on a group of 250 unrelated persons from various regions of Poland, revealed the presence of 24 different alleles ranging in size from 232 to 290 base pairs. Analysis of the sequenced fragments demonstrated that the alleles consisted of two flanking regions and two variable blocks that were separated by a consensus sequence. There were (AAAG)(5)(AG)(1)(AAAG)(3-4) repeats in the first block, and [(AAAG)(2)(AG)(1)](0-1)[(AAAG)(6)(AG)(1)](0-1)(AAAG)(n) repeats in the second block. On the basis of the allele frequencies in the population, we were able to do biostatistical calculations, which gave the following results: expected heterozygosity 0.8947 +/- 0.0137, power of discrimination 0.9793, polymorphism information content 0.8837, probability of exclusion (PE) 0.7859, PE for motherless cases 0.6473, and an average paternity index of 4.7470. These biostatistical parameters show that the marker D17S2266E can find a wide range of applications in forensic testing.