The single most polymorphic STR Locus: SE33 performance in U.S. populations

The STR locus SE33 (ACTBP2) located on chromosome 6 (6q14) is arguably the most polymorphic marker examined thus far by the forensic community with a heterozygosity of >0.95 in some populations. Three different primer sets were utilized in this study in order to assess the possibilities of primer binding site mutations. Population variation was measured in 460 U.S. Caucasian, 445 African American, 336 Hispanic, and 202 Asian samples along with mutation rates from almost 400 father–son pairs. In addition, the 10 genomic DNA components in NIST Standard Reference Material SRM 2391b were sequenced and found to exhibit a variety of additional base changes, insertions, and deletions outside of the SE33 repeat region.     

Unusual FGA and D19S433 off-ladder alleles and other allelic variants at the STR loci D8S1132, vWA, D18S51 and ACTBP2 (SE33)

A very short FGA allele *14 and a long D19S433 allele *19.2 were detected and sequenced, as well as the new D8S1132 alleles *12.1, *14 and *15.1. Further new sequence data (vWA allele *18.3, D18S51 allele *11.2, SE33 alleles *24.2, *32, *34 and *37, including the rare variant allele *13.2) are described.     

Further allelic variation at the STR-loci ACTBP2 (SE33), D3S1358, D8S1132, D18S51 and D21S11

ACTBP2 (SE33), D3S1358, D8S1132, D18S51 and D21S11 are frequently used STR-loci in the forensic field. This study reports sequence data of further new or rare alleles at these loci, varying in length or in sequence, which were detected in course of investigations for various purposes.     

Sequence analysis of STR polymorphisms at locus ACTBP2 in the Taiwanese population

A highly polymorphic sequence structure is reported in the human beta-actin related pseudogene 2 (ACTBP2) (SE33) locus in members of the Taiwanese Han population. A total of 100 unrelated members of the Taiwanese Han population were used in the study. Alleles that shared the same size but differ in their sequence are described to allow for inter laboratory sharing of data. PCR products amplified from this locus were separated by single-strand conformation polymorphism electrophoresis, the single-stranded DNA bands were excised from the gels, a second amplification performed, and then the PCR products were sequenced. All the alleles differed by either 2 or 4 bp. Sequence variations were observed as deletions or insertions in the repeat units AG (or AA) and AAAG. Additionally, transitions in the flanking regions were recorded. A total of 27 alleles with 71 associated genotypes were recorded if the alleles were defined by size, but 68 alleles with 88 associated genotypes were noted with the alleles were scored on the basis of sequence variation. The power of discrimination (Pd) of this single locus was 0.9874 making the human ACTBP2 a good alternative marker for individual identification and paternity testing.     

Sequence analysis of STR polymorphisms at locus ACTBP2 in the Taiwanese population

A highly polymorphic sequence structure is reported in the human beta-actin related pseudogene 2 (ACTBP2) (SE33) locus in members of the Taiwanese Han population. A total of 100 unrelated members of the Taiwanese Han population were used in the study. Alleles that shared the same size but differ in their sequence are described to allow for inter laboratory sharing of data. PCR products amplified from this locus were separated by single-strand conformation polymorphism electrophoresis, the single-stranded DNA bands were excised from the gels, a second amplification performed, and then the PCR products were sequenced. All the alleles differed by either 2 or 4 bp. Sequence variations were observed as deletions or insertions in the repeat units AG (or AA) and AAAG. Additionally, transitions in the flanking regions were recorded. A total of 27 alleles with 71 associated genotypes were recorded if the alleles were defined by size, but 68 alleles with 88 associated genotypes were noted with the alleles were scored on the basis of sequence variation. The power of discrimination (Pd) of this single locus was 0.9874 making the human ACTBP2 a good alternative marker for individual identification and paternity testing.     

Allele frequencies of the ACTBP2 (=SE33), D18S51, D8S1132, D12S391, D2S1360, D3S1744, D5S2500, D7S1517, D10S2325 and D21S2055 loci in a German population sample

A population study on 10 tetrameric STR loci (ACTBP2 (=SE33), D18S51, D8S1132, D12S391, D2S1360, D3S1744, D5S2500, D7S1517, D10S2325, D21S2055) was performed with Germans from Bavaria.     

Population genetics of ACTBP2 (SE33) in Western Saxony (Germany)

In order to apply a useful STR system we performed a population study in Western Saxony (Germany). The allele distribution was investigated in a sample of 431 unrelated adults. In addition, 170 families from routine paternity cases were examined for the presence of meiotic mutations, and two mutations were observed.     

Allele frequencies of 13 short tandem repeat (STR) loci in the Romanian population

A population study on 13 tetra- and pentameric STR loci (D3S1358, VWA, D8S1179, D21S11, D18S51, D16S539, D2S1338, D19S433, THO1, FGA, ACTBP2 (SE33), Penta D and Penta E) was performed with Romanians from the Bucharest area.     

Allele frequencies of sixteen STRs in the population of Northern Portugal

Allele frequencies of sixteen autossomal short tandem repeats (STRs), D3S1358, VWA, D16S539, D8S1179, D21S11, D18S51, TH01, FGA, D5S818, D13S317, D7S820, TPOX, CSF1PO, Penta D, Penta E (included in the PowerPlex 16 kit), and the SE33 (PowerPlex ES Monoplex System SE33) were determined in a sample of 200 healthy unrelated individuals from the north of Portugal.     

Sequence‐based Saudi population data for the SE33 locus

A set of 87 reference samples collected from the population of Saudi Arabia were sequenced using the ForenSeq™DNA Signature Prep Kit on a MiSeq FGx™. The FASTQ files contain the sequences of the SE33 STR, but are not reported by the ForenSeq™ Universal Analysis Software (UAS). The STRait Razor software was used to recover and to report SE33 sequence‐based data for the Saudi population. Ninety-six sequence-based alleles were recovered, most of which had previously reported motif patterns. Two unreported motif patterns found in three alleles and seven novel allele sequences were reported. We also reported a single discordance between the sequence-based data and the CE data that was due to the presence of a common TTTT deletion. SE33 had 130% more sequence-based alleles; the highest number of observed sequence variants were in alleles 27.2 and 30.2, which each had 7 sequence variants. The statistical parameters emphasize the usefulness of using the sequence-based data.     

An ambiguous sequence-based allele of SE33

SE33 was a well-known autosomal short tandem repeat (STR) marker that was high polymorphic and therefore was high discrimination power. The sequence structure of STR markers has been increasingly explored with next-generation sequencing (NGS) technology. The sequencing resulted in the development of a new locus designation and allele nomenclature that was also backward compatible with the conventional capillary electrophoresis. SE33 was one of the STR markers that had been coamplified by Forenseq™ Signature Prep Kit (Verogen) but were not analyzed and illustrated in the Universal Analysis Software (UAS) (Verogen). This study reported an ambiguous sequence-based allele 16.3 of the SE33 locus. This allele was observed while analyzed by STRait Razor 3.0. The configuration file was modified from the previous studies to include 15 bp of 5′ flanking region and 24 bp of 3′ flanking region. The ambiguous allele was called 16.3 (106 bp) with a read count of 2070. However, the sequence of the repeat region cannot be designated as allele 16.3. Several possible scenarios for allele designation were presented and discussed.     

短串联重复位点ACTBP2(SE33)的扩增片段长度多态性研究

应用变性聚丙烯酸胺凝胶电泳（dn－PAGE）结合银染色技术对短串联重复（STR）位点ACTBP2（SE33）的扩增片段长度多态性（Amp－FLPs）进行了研究。在210名无关中国个体中观察到了25个等位基因，等位基因频率分布在0．007～0．093之间。基因型的分布符合Hardy－Weinberg定律，个体识别能力（DP）值为0．99，杂合度（H）为98．7％。七个家系分析的结果表明，该位点的遗传符合孟德尔遗传法则，未观察到变异。对几种常见的法医物证检材的分析表明，该分型系统对DNA降解放为严重的检村适用性强，而且灵敏度高（0．5ng），适合于法医学实际应用。     

Rare PGM1 (6) and PGM1(7) alleles in the Polish population

Rare PGM1 phenotypes, 6-1, 6-2 and 7-2, were detected in blood samples from 3,437 non-related adults using electrophoresis in starch-gel and cellulose acetate membranes. Frequencies of 0.0009 and 0.0008 were calculated for PGM1(6) and PGM1(7), respectively, for a population from northern Poland. The variants had been inherited, which was confirmed by family studies.     

1066例新疆汉族人群21个常染色体STR基因座遗传多态性分析

目的研究21个常染色体STR基因座(CSF1PO,D3S1358,D5S818,D7S820,D8S1179,D13S317,D16S539,D18S51,D21S11,FGA,TH01,VWA,D2S1338,D19S433,D1S1656,D12S391,D2S441,D10S1248,TPOX,D22S1045,SE33)在新疆汉族人群中的遗传多态性。方法用GlobalFiler^TM R PCR Amplification荧光标记试剂盒对1066例新疆汉族无关个体的DNA进行PCR扩增,3500遗传分析仪电泳分析,用GeneMapper■ID-X v1.4软件分析等位基因片段大小,用Modified-Powerstates和Arlequin v3.5分析软件进行等位基因频率和法医学常用参数统计分析。结果在新疆汉族人群中,21个常染色体STR基因座不存在连锁不平衡现象,基因型分布符合Hardy–Weinberg平衡,共检出282个等位基因和1147种基因型,杂合度期望值(He)范围从0.6291(TPOX)到0.9428(SE33),多态信息含量(PIC)范围从0.5648(TPOX)到0.9393(SE33),累计个体识别率(CDP)>0.99999999999999999999。结论新疆汉族人群21个常染色体STR基因座具有较高多态性,可以用于法医学亲权鉴定和个体识别,也可以用于人类学和遗传学研究。     

Post-mortem SNP analysis of CYP2D6 gene reveals correlation between genotype and opioid drug (tramadol) metabolite ratios in blood

Tramadol is an opioid drug metabolised in phase I by cytochrome P450 (CYP) enzymes, of which CYP2D6 is mainly responsible for the O-demethylation of tramadol, but is not involved in N-demethylation. Defects in the genes encoding drug metabolising enzymes (DMEs) may lead to adverse drug effects, even to death. To aid interpretation of the forensic toxicology results, we studied how the genetic variation of the CYP2D6 gene is reflected in tramadol metabolite ratios found in post-mortem samples. In 33 Finnish autopsy cases where tramadol was found, we analysed both the CYP2D6 genotype and the concentrations of tramadol and its metabolites O- and N-demethyltramadol. As expected, we found a correlation between the number of functional CYP2D6 alleles and the ratio of tramadol to O-demethyltramadol. We also found a correlation between the number of functional alleles and the ratio of tramadol to N-demethyltramadol. This can be explained by the complementary nature of the two main tramadol demethylation pathways. No known CYP2D6 inhibitors were associated with exceptional metabolic ratios. Furthermore, no accidental tramadol poisonings were associated with a defective CYP2D6 gene. Our results on the tramadol are among the first to demonstrate that genetic variation in drug metabolising enzymes can be analysed in post-mortem blood, and that it correlates well with the parent drug to metabolite ratios. The results also suggest that genetic factors play, in general, a dominant role over other factors in the metabolism of individual drugs.     

Combined phenotyping of glucose 6-phosphate dehydrogenase (G6PD; EC 1.1.1.49) and 6-phosphogluconate dehydrogenase (PDG; EC 1.1.1.44)

The addition of negroid phenotypes to the already heterogeneous population of Israel caused us to reuse the enzymes G6PD and PGD which are known to have a better discrimination power in a negroid population than in caucasians. We have developed a system for combined phenotyping of G6PD and PGD. This system answers the requirements of the above enzymes and results in a negroid population than in caucasians. We have developed a system for combined phenotype-amount of sample and reagents needed and time spent.     

Forensic and population genetic analysis of Serbian population using 21 STR loci of GlobalFiler™ PCR amplification kit

Autosomal short tandem repeats (STRs) have been widely used in forensic investigations. Prior to the application of any DNA based identification method, it is essential to estimate the allele frequencies and forensic statistical parameters of targeted STR loci in each population in order to provide a more precise reference database for forensic investigation. The GlobalFiler™ Kit is a multiplex assay that combines the 13 original CODIS loci with 7 non-overlapping loci from the expanded European Standard Set (ESS), as well as the highly discriminating SE33 locus, two Y-based loci and the sex determining maker, Amelogenin. The full complement of loci in the GlobalFiler™ Kit are: D13S317, D7S820, D5S818, CSF1PO, D1S1656, D12S391, D2S441, D10S1248, D18S51, FGA, D21S11, D8S1179, vWA, D16S539, TH01, D3S1358, AMEL, D2S1338, D19S433, DYS391, TPOX, D22S1045, SE33 and a Y-specific insertion/deletion locus (Yindel). The 6-dye GlobalFiler™ PCR Amplification kit (ThermoFisher Scientific) comprises 21 autosomal STRs have already been proven to be able to provide reliable DNA profiling results and enhance the power of discrimination between individuals. In this study, we are presenting an analysis of GlobalFiler STR loci on 209 unrelated individuals from Serbia.     

STR data for the AmpFlSTR Profiler Plus loci from Murcia region (SE Spain)

Frequency data of the nine STRs included in the AmpFlSTR Profiler Plus Kit were determined in a sample of 114 unrelated individuals from Murcia region (SE Spain).     

Reliability of SE33 typing by capillary electrophoresis

A ladder of 24 ACTBP2 (SE33) alleles was separated 175 times by denaturing capillary electrophoresis on an ABI Prism 310 Genetic Analyzer using polymer POP-4. The mean standard deviation of fragment size determination was 0.083 bp. Fragments in the whole allelic range of ACTBP2 could be typed with high precision and reproducibility if adjacent fragments differed by at least two nucleotides. The capacity of resolving 1 bp differences was tested by repeatedly running a ACTBP2*14.2/14.3/31.2/31.3 allelic mixture. The 14.2/14.3 fragment pair could be separated in 98%, the 31.2/31.3 fragment pair only in 65% of all runs. Reliable separation of this difficult fragment mixture could exclusively achieved by using POP-6.