Allele frequency data for 23 aSTR for different ethnic groups from Republic of Zimbabwe

Analysis of data and common mutations encountered during routine parentage testing in Zimbabwe

We analyzed parentage data collected over a ten-year period in a Zimbabwean DNA testing laboratory. Parentage case types, prevalence, exclusion data, mutations rates and observed genotyping irregularities were analyzed. We report analysis results from 1303 cases. DNA extraction and STR typing was conducted using standard commercial kits. Paternity was the most requested test (87.37%) followed by the indirect biological kinship tests (7.01%). Duo paternity (motherless) was the most common paternity test for both regular and court cases. We observed 367 paternity exclusions from 1135 cases, giving an overall paternity exclusion rate of 32.33%. Maternity had the lowest exclusion rate (8.33%), with criminal cases having the highest paternity (61.11%) and maternity (33.33%) exclusion rates. The number of mismatched STR loci ranged from 2-12 for duo cases and 4-18 for the trio cases. FGA, D2S1338, D18S51 and D2S441 were the most informative markers for exclusion. We detected 30 mutations out of 837 cases with an estimated paternal and maternal mutation rate of 0.0021 and 0.0011 respectively. Triallelic patterns were only observed at the TPOX locus with allele 10 and 11 being the extra alleles transmitted. Our report provides forensic parameters which can improve parentage and forensic analysis in Zimbabwe.

Allelic frequencies distribution and forensic parameters of 23 autosomal short tandem repeats in the population of the State of Pernambuco, Brazil

Located in the Northeast Region, the Pernambuco State is one of the 27 federative units of Brazil. Here, we determined populational data for 23 short tandem repeat (STR) markers - CSF1PO, FGA, TH01, TPOX, vWA, D1S1656, D2S1338, D2S441, D3S1358, D5S818, D7S820, D8S1179, D10S1248, D12S391, D13S317, D16S539, D18S51, D19S433, D21S11, D22S1045, PENTA D, PENTA E and SE33 - of the Pernambuco population. The sample consisted of 767 healthy, adult, unrelated individuals (437 males, 330 females) born and resident in the State of Pernambuco. STRs were amplified using three multiplex kits, according to the availability: PowerPlex® Fusion 6C System (Promega Corporation), PowerPlex® Fusion System (Promega Corporation) and GlobalFiler™ Express (Thermo Fisher Scientific). Allelic frequencies, forensic parameters and Hardy-Weinberg equilibrium determinations were estimated for all the 23 loci. No deviations from the Hardy-Weinberg equilibrium were observed for any of the markers, after Bonferroni correction. We observed that the most and less informative markers were SE33 and TPOX, respectively. The combined power of discrimination (CPD) was 0.99999999999999999999999999999, and the combined power of exclusion (CPE) was 0.99999999997. The cumulative typical paternity index was 37,919,301,869.3021. Interpopulation analyses (Nei's genetic distance) based on the expanded CODIS core loci was performed between the Pernambuco sample and other global populations. Pernambuco was the closest Brazilian population to African group and stayed distant from the Native American group. This work contributed to show that a panel of 23 autosomal STR loci is very informative, being able for forensic applications related in this population.