STR allele sequence variation: Current knowledge and future issues

This article reviews what is currently known about short tandem repeat (STR) allelic sequence variation in and around the twenty-four loci most commonly used throughout the world to perform forensic DNA investigations. These STR loci include D1S1656, TPOX, D2S441, D2S1338, D3S1358, FGA, CSF1PO, D5S818, SE33, D6S1043, D7S820, D8S1179, D10S1248, TH01, vWA, D12S391, D13S317, Penta E, D16S539, D18S51, D19S433, D21S11, Penta D, and D22S1045. All known reported variant alleles are compiled along with genomic information available from GenBank, dbSNP, and the 1000 Genomes Project. Supplementary files are included which provide annotated reference sequences for each STR locus, characterize genomic variation around the STR repeat region, and compare alleles present in currently available STR kit allelic ladders. Looking to the future, STR allele nomenclature options are discussed as they relate to next generation sequencing efforts underway.     

Genetic polymorphism data on 15 autosomal STR markers in a Western Romanian population sample

The allelic frequency distribution and statistical genetic parameters of forensic relevance for 15 STR loci (D8S1179, D21S11, D7S820, CSF1PO, D3S1358, TH01, D13S317, D16S539, Penta E, Penta D, vWA, TPOX, D18S51, D5S818 and FGA) in a population sample of 336 non-related individuals residing in the Western part of Romania are presented.     

Massively parallel sequencing data of 31 autosomal STR loci obtained using the Precision ID GlobalFiler NGS STR Panel v2 for 82 Japanese population samples

Allele frequencies for 31 autosomal short tandem repeat (STR) loci (CSF1PO, D10S1248, D12ATA63, D12S391, D13S317, D14S1434, D16S539, D18S51, D19S433, D1S1656, D1S1677, D21S11, D22S1045, D2S1338, D2S1776, D2S441, D3S1358, D3S4529, D4S2408, D5S2800, D5S818, D6S1043, D6S474, D7S820, D8S1179, FGA, Penta D, Penta E, TH01, TPOX, and vWA) were obtained using Precision ID GlobalFiler NGS STR Panel v2 from 82 unrelated individuals sampled from the Japanese population. Autosomal STR alleles designated by NGS and conventional capillary electrophoresis were found to be concordant except at D2S441 allele 9.     

Genetic variation of 15 autosomal short tandem repeat (STR) loci in the Palestinian population of Gaza Strip

Fifteen autosomal STR loci included in the PowerPlex^®16 System were typed in a population sample of 125 unrelated individuals from Palestinian population of Gaza Strip. Allele frequencies, Hardy–Weinberg equilibrium and forensic parameters were determined for the following loci: Penta E, D18S51, D21S11, TH01, D3S1358, FGA, TPOX, D8S1179, vWA, Penta D, CSF1PO, D16S539, D7S820, D13S317 and D5S818.     

Population genetic data on 15 autosomal STRs in a Pakistani population sample

Allele frequencies for the 15 STR loci (D3S1358, TH01, D21S11, D18S51, Penta E, D5S818, D13S317, D7S820, D16S539, CSF1PO, Penta D, VWA, D8S1179, TPOX and FGA) were investigated using PowerPlex^®16 amplification kit in a sample of 328 unrelated individuals from Islamic Republic of Pakistan. The allelic distributions were in Hardy Weinberg equilibrium for all loci except for the loci FGA, TPX and THO1. Various forensic indices were calculated and a comparison was made with geographically nearby populations.     

Bosnian population data for the 15 STR loci in the Power Plex 16 kit

The PowerPlex 16 amplification kit was used for the analysis of allele frequencies for the 15 STR loci (D3S1358, TH01, D21S11, D18S51, Penta E, D5S818, D13S317, D7S820, D16S539, CSF1PO, Penta D, VWA, D8S1179, TPOX and FGA) in unrelated, autochthonous healthy adults from Bosnia (n=123 for TH01, Penta E, D16S539, CSF1PO, Penta D and TPOX, n=210 for D3S1358, D21S11, D18S51, D5S818, D13S317, D7S820, VWA, D8S1179 and FGA). The agreement with HWE was confirmed for all loci with the exception of Penta D (based on the ²-test only). The combined power of discrimination (PD) and the combined power of exclusion (PE) for the 15 studied loci were 0.999999999999999997 and 0.999999, respectively.     

Population data for 12 STR loci in Hong Kong Chinese

The allele distributions at the 12 short tandem repeat (STR) loci D3S1358, HUMvWA, HUMFIBRA/FGA, HUMTHO1, HUMTPOX, HUMCSF1P0, D5S818, D13S317, D7S820, D8S1179, D21S11 and D18S51 have been determined for 284 unrelated Chinese in Hong Kong. The combined probability of identity for the 12 STR loci was about 4.1 × 10^–14 and the overall probability of excluding paternity 0.999978. None of the 12 loci were found to deviate from Hardy-Weinberg expectations according to the results of the exact test. There was also little evidence for association of alleles between loci. The results demonstrate that the loci are useful for forensic human identification and parentage testing for the Chinese population in Hong Kong. Received: 2 December 1999 / Accepted: 12 April 2000     

Genetic analysis of Kashmiri Muslim population living in Pakistan

The PowerPlex 16 amplification kit was used for the analysis of allele frequencies for the 15 STR loci (D3S1358, TH01, D21S11, D18S51, Penta E, D5S818, D13S317, D7S820, D16S539, CSF1PO, Penta D, vWA, D8S1179, TPOX and FGA) in unrelated, autochthonous healthy adults from Kashmiri refugee population in Pakistani Punjab (n=125). The allelic distributions were in Hardy-Weinberg equilibrium in all of loci examined except for the vWA locus. Forensic parameters were calculated and a comparison was made with geographically nearby populations.     

Analysis of 15 short tandem repeats reveals significant differences between the Arabian populations from Morocco and Syria

The short tandem repeat (STR) systems D3S1358, TH01, D21S11, D18S51, Penta E, D5S818, D13S317, D7S820, D16S539, CSF1PO, Penta D, vWA, D8S1179, TPOX and FGA were studied in Arabian population samples from Morocco and Syria. No significant deviation from Hardy-Weinberg equilibrium could be observed in either preparation. Comparing the Moroccan and Syrian populations using the program RxC, no similarity could be observed at all 15 loci. In the Moroccan and Syrian populations the matching probability is 1 in 1.4 x 10(17) and 1 in 2.6 x 10(17), respectively. Thus, the combination of these 15 STR loci is powerful tool for forensic identification in Arabian populations.     

Genetic polymorphisms of 20 STR loci in a Chaoshan group from Jieyang,China

We obtained allelic frequencies and forensic parameters of 20 short tandem repeat (STR) loci (D3S1358, FGA, D5S818, D7S820, CSF1PO, D16S539, D19S433, vWA, D8S1179, D18S51, D13S317, TPOX, TH01, D2S1338, D12S391, D1S1656, D21S11, D6S1043, Penta D, Penta E) from 529 unrelated individuals in Jieyang Han population using PowerPlex® 21 (Promega, Madison, Wi, USA). The relationship between the Jieyang Han group and other Han populations was studied and the results showed that the Jieyang Han population had the closest genetic relationship with the Fujian Han population.     

Allele frequency data for 17 short tandem repeats in a Czech population sample

Allele frequencies for 17 short tandem repeats (STRs) autosomal loci (D2S1338, D3S1358, D5S818, D7S820, D8S1179, D13S317, D16S539, D18S51, D19S433, D21S11, CSF1PO, FGA, PentaD, PentaE, TH01, TPOX, vWA) were studied in an extensive sample (max. N = 1411) of unrelated individuals originating from the Czech Republic. Population and forensic parameters were estimated. Except for FGA and Penta E loci, no deviations from the Hardy–Weinberg equilibrium were detected. A comparative analysis with published data revealed significant differences in allele frequencies for some loci from the Polish population and three Hungarian populations (Ashkenazim population and Romany populations from Debrecen and Baranya County, respectively). A combination of these 17 STR loci provides a powerful tool for forensic identification in the native Czech population.     

Autosomal STR variations in three endogamous populations of West Bengal, India

The allele frequency distribution of 15 autosomal STR loci was determined using AmpFlSTR Identifiler kit in three endogamous caste populations namely, Rajbanshi, Paliya and Dhimal from northern regions of West Bengal, India. The study includes 13 CODIS STR core markers, i.e., D8S1179, D3S1358, D21S11, D7S820, CSF1PO, vWA, TPOX, D18S51, THO1, D13S317, D16S539, D5S818, FGA and two other loci D19S433 and D2S1338. All the loci followed Hardy-Weinberg equilibrium, except loci D8S1179, vWA and FGA in Rajbanshi population, D13S317 in Paliya population and D16S539 and TPOX in Dhimal population. The allele 12 in CSF1PO in Rajbanshi population and allele nine in THO1 in Paliya as well as in Dhimal population were found to be most frequent. All the 15 STR loci studied were found to be highly polymorphic with respect to observed heterozygosity values. Population differentiation tests revealed highly significant differences at several loci suggesting the endogamous nature of studied populations. STR allele frequency data on Dhimal population presented here is a unique contribution to the existing DNA data base on Indian population. To the best of our present knowledge, hitherto Dhimal Population has not been explored genetically for generating forensic data on STR markers.     

Genetic polymorphism studies on 22 autosomal STR loci of the PowerPlex Fusion System in Bangladeshi population

Genetic polymorphism of 22 autosomal STR loci included in PowerPlex® Fusion System (D3S1358, D1S1656, D2S441, D10S1248, D13S317, Penta E, D16S539, D18S51, D2S1338, CSF1PO, Penta D, TH01, vWA, D21S11, D7S820, D5S818, TPOX, D8S1179, D12S391, D19S433, FGA and D22S1045) was studied in 188 unrelated Bangladeshi Bengali individuals. Allele frequencies and forensic efficiency parameters such as, the power of discrimination (PD), observed and expected heterozygosity (Ho & He), polymorphism information content (PIC), probability of match (PM), power of exclusion (PE) and typical paternity index was calculated for the loci. The combined PM and PE for all 22 STR loci were calculated to be 5.29 × 10⁻²⁷ and 0.99999999945 respectively. The dataset indicated the usefulness of these loci in personal identification, parentage testing and complex kinship analysis in Bangladeshi population. A neighbor-joining tree was constructed based on pair-wise Nei’s genetic distance by comparing allele frequency data for the 22 loci with six other populations. The analysis showed that Bangladeshi population lies closer to a clade consisting Japan, the Philippines and East Timot populations.     

Genetic diversity of 21 autosomal STR loci in the Han population from Sichuan province,Southwest China

Exploration of the ethnic origin and genetic differentiation of 56 Chinese officially recognized nationalities populations played a fundamental role in the research field of population genetics, forensic science, linguistics, anthropology, and archaeology. In the present study, population data of 21 autosomal STR loci (CSF1PO, D10S1248, D12S391, D13S317, D16S539, D18S51, D19S433, D21S11, D2S1338, D2S441, D3S1358, D5S818, D6S1043, D7S820, D8S1179, FGA, Penta D, Penta E, TH01, TPOX, and vWA) included in the AGCU EX22 kit in 2793 Southwest Han Chinese individuals was obtained and population genetic relationships among 28 Chinese populations were investigated. Our study indicated that the twenty-one autosomal STRs are highly polymorphic in the Sichuan Han population and can be used as a powerful tool in the routine forensic usage. MDS and phylogenetic analysis suggested that the Sichuan Han population kept a close genetic relationship with the southwest populations.     

The Fang population of Equatorial Guinea characterised by 15 STR-PCR polymorphisms

Allele frequencies for 15 STR loci (D8S1179, D21S11, D7S820, CSF1PO, D19S433, HUMVWA31A, HUMTPOX, D18S51, D3S1358, HUMTHO1, D13S317, D16S539, D2S1338, D5S818 and HUMFGA) were analysed in the Fang population of Bioko Island, Equatorial Guinea. No deviation from Hardy-Weinberg equilibrium was found for all loci. Statistical parameters demonstrated the forensic utility of the analysed systems.     

Population genetic data for 17 STR markers from Lebanon

Seventeen autosomal STRs were analyzed (D2S1338, D3S1358, D5S818, D7S820, D8S1179, D13S317, D16S539, D18S51, D19S433, D21S11, CSF1PO, FGA, TH01, TPOX, vWA, Penta D, and Penta E) in the Lebanese population. A total of 192 unrelated individuals were genotyped for the 15 autosomal STRs in the Promega PowerPlex 16 STR kit. An additional 275 unrelated individuals were genotyped for the Applied Biosystems AmpFlSTR Identifiler and SGM + STR kits. Allele frequencies for the shared CODIS 13 loci among the three STR kits tested were not significantly different among individuals within the Lebanese population. Forensic and population genetic parameters for the 17 loci were calculated. We also compared the allele frequencies from this population with other populations in the same geographic vicinity.     

Developmental validation of the Huaxia™ Platinum PCR amplification kit: A 6-dye multiplex direct amplification assay designed for Chinese reference samples

The Huaxia™ Platinum Kit for short tandem repeat (STR) amplification was designed to meet the needs of the rapidly growing Chinese forensic database. This PCR multiplex allows simultaneous amplification of the following autosomal loci: D3S1358, vWA, D16S539, CSF1PO, TPOX, D8S1179, D21S11, D18S51, Penta E, D2S441, D19S433, TH01, FGA, D22S1045, D5S818, D13S317, D7S820, D6S1043, D10S1248, D1S1656, D12S391, D2S1338, Penta D and the gender-identification markers Yindel, and AMEL.The Huaxia™ Platinum Kit enables direct amplification from blood and buccal samples stored on treated and untreated paper, and features an optimized PCR protocol that yields time to results in less than 45 min. Developmental validation testing followed SWGDAM guidelines and demonstrated that this assay produces reproducible and accurate results. Studies on 798 individuals in 4 major Chinese ethnic groups produced highly concordant results with other commercially available STR genotyping kits. The validation results demonstrate that the Huaxia™ Platinum Kit is a robust and reliable identification system for forensic DNA databasing applications.     

Analysis of eight STR loci in two Hungarian populations

A multiplex reaction for the eight STR loci D3S1358, FGA, D8S1179, D21S11, D18S51, D5S818, D13S317, D7S820 was used to generate allele frequency databases for two Hungarian population samples, Caucasians from the Budapest area and Romanies from Baranya county. During the analysis two intermediate-sized alleles and a sequence variant allele were observed at the D7S820 locus. All three types of allelic variants were found to have modifications in the same block of a (T)₉ stretch located within the 3′ flanking region of each allele, which may indicate a possible higher mutation rate of this (T)₉ block. For the loci D3S1358 and D7S820 the Romany population database showed departures from Hardy-Weinberg equilibrium. The forensic efficiency values for the Romany population were slightly different from those found in the Hungarian Caucasian population. Comparing the allele frequency values by G-statistic, calculating the F_ST indices and with the pair-wise comparisons of inter-population variance, the two Hungarian populations could be distinguished using data from the eight STR loci. Received: 18 May 1999 / Received in revised form: 26 August 1999     

Allele frequencies of 37 short tandem repeat loci in a Japanese population

Allele frequencies for 37 STR autosomal loci (D1S1656, D2S1338, D2S1360, D2S441, D3S1358, D3S1744, D4S2366, D5S2500, D5S818, D6S474, D7S1517, D7S820, D8S1132, D8S1179, D10S1248, D10S2325, D12S391, D13S317, D16S539, D18S51, D19S433, D21S11, D21S2055, D22S1045, CSF1PO, F13A01, F13B, FESFPS, FGA, LPL, Penta C, Penta D, Penta E, SE33, TH01, TPOX, vWA) were obtained from a sample of 175 unrelated individuals in a Japanese population.     

Genetic analysis of 15 autosomal and 12 Y-STR loci in the Espirito Santo State population, Brazil

This study provides population genetic data for individuals of Vitoria, Espirito Santo, Brazil, a location not yet characterized for STR frequencies used for genetic identification studies. Allelic frequencies and other population data analysis are reported for the 15 autosomal-STR loci included in the PowerPlex(?)16 kit (CSF1PO, D13S317, D16S539, D18S51, D21S11, D3S1358, D5S818, D7S820, D8S1179, FGA, Penta D, Penta E, TPOX, TH01 and vWA). Allele and haplotype frequencies, gene diversity and discrimination capacity were also estimated for the PowerPlex(?) Y System (DYS19, DYS385, DYS389I/II, DYS390, DYS391, DYS392, DYS393, DYS437, DYS438 and DYS439). Blood samples were obtained from 226 unrelated volunteers (135 males and 91 females) residents in the city of Vitoria, representing a typical sample of the mixed ethnicity present in the Espirito Santo State, Brazil. Within the tested population, the total number of individuals typed for specific markers is: 226 for D13S317, D21S11, D3S1358, D7S820, D8S1179 and FGA; 225 for D16S539 and D5S818; 224 for D18S51; 223 for CSF1PO; 222 for Penta D and vWA; 220 for Penta E; 207 for TPOX and 142 for TH01. Y-STR haplotypes were analyzed for 102 unrelated males, being 71 of them present in the 135 autosomal-STR sample, and 31 new males tested only for Y-STR markers. All autosomal markers were in Hardy-Weinberg Equilibrium. Y-STR analysis identified 101 haplotypes, being 100 of them unique.