Population genetic data of the 21 autosomal STRs included in GlobalFilerTM kit of a population sample from the Kingdom of Bahrain

IntroductionBahrain’s population consists mainly of Arabs, Baharna and Persians leading Bahrain to become ethnically diverse. The exploration of the ethnic origin and genetic structure within the Bahraini population is fundamental mainly in the field of population genetics and forensic science.AimThe purpose of the study was to investigate and conduct genetic studies in the population of Bahrain to assist in the interpretation of DNA-based forensic evidence and in the construction of appropriate databases.Materials and Methods24 short-tandem repeats in the GlobalFiler™ PCR Amplification kit including 21 autosomal STR loci and three gender determination loci were amplified to characterize different genetic and forensic population parameters in a cohort of 543 Bahraini unrelated healthy men. Samples were collected during the year 2017.ResultsThe genotyping of the 21 autosomal STRs showed that most loci were in Hardy-Weinberg Equilibrium (HWE) except for three markers; D3S1358, D19S433 and D5S818 which showed deviation from HWE. We also found out no significant deviations from LD between pairwise STR loci in Bahraini population except when plotting for D3S1358-CSF1PO, CSF1PO-SE33, D19S433-D12S391, FGA-D2S1338, FGA-SE33, FGA-D7S820 and D7S820-SE33. The SE33 locus was the most polymorphic for the studied population and THO1 locus was the less polymorphic. The Allele 8 in TPOX scored the highest allele frequency of 0.496. The SE33 locus showed the highest power of discrimination (PD) in Bahraini population, whereas TPOX showed the lowest PD value. The 21 autosomal STRs showed a value of combined match probability (CMP) equal to 4.5633E-27, and a combined power of discrimination (CPD) of 99.99999999%. Off-ladders and tri-allelic variants were observed in various samples at D12S391, SE33 and D22S1045 loci.ConclusionOur study indicated that the twenty-one autosomal STRs are highly polymorphic in the Bahraini population and can be used as a powerful tool in forensics and population genetic analyses including paternity testing and familial DNA searching.Author SummaryKingdom of Bahrain is a country of 33 islands located in the Arabian Peninsula. The location of Bahrain had affected the diversity of its population, which is mainly divided into four main ethnic groups: Arabs, Baharna and Persians. Genetic studies on Bahraini population are very limited and little has been done to characterize population structure within Kingdom of Bahrain. Here, we used 21 autosomal STRs included in the GlobalFiler™ Amplification Kit to amplify DNA from 543 non-related males from Bahraini population. We conducted statistical analysis using two main different software such as STRAF and GenAlEx. Different forensic and population parameters were obtained to characterize Bahraini population. Some of the significant results obtained were the following: most of the loci were in Hardy-Weinberg Equilibrium, the most polymorphic and informative marker was SE33. Allele 8 in TPOX presented the highest allele frequency for the studied population. We also found out some of the rare variants which were recorded in STRbase website. Bahraini population was correspondingly compared to the genetic structure of the region. Our study indicated the usefulness of the 21 autosomal STRs in the GlobalFiler ™ in establishing databases, analyzing paternity and reviewing DNA-based evidences.