Phylogenetic analysis and forensic evaluation among Rakhine, Marma, Hajong, and Manipuri tribes from four culturally defined regions of Bangladesh using 17 Y-chromosomal STRs.

We have analyzed haplotypes for 17 Y chromosomal STR loci in Bangladeshi mainstream Bengali population and four largest ethnic groups inhabiting the North-Eastern and Southern region of Bangladesh using AmpFlSTR® Yfiler® PCR amplification systems. A total of 667 haplotypes from Bangladeshi Bangali, 157 from Rakhine, 144 from Marma, 112 from Hajong, and 136 from Manipuri individuals were observed with corresponding discrimination capacity (DC) of 0.973 for Bengali, 0.723 for Rakhine, 0.743 for Marma, 0.794 for Hajong, and 0.720 for Manipuri groups, respectively. In order to investigate genetic relationship and the pattern of paternal contributions of the studied population, a comparison of the studied data with the published data from Y-STR haplotype reference database (YHRD) was conducted based on analysis of molecular variance (AMOVA). Construction of neighbour-joining tree revealed that the Rakhine population lies closer to a clade consisting, Korean and Japanese population. The Hajong population showed close affinity with Riang (Tripura, India) tribe followed by Marma population. On the other hand, Manipuri group is closely related to Thai population followed by Tamil and mainstream Bengali population.

Genetic diversity study on 12 X-STR loci of investigator® Argus X STR kit in Bangladeshi population.

The X-chromosome short tandem repeat (STR) loci are of particular interest for solving complex kinship and paternity cases. Here, we report the genetic data from 209 unrelated Bangladeshi individuals (102 males and 107 females) that were genotyped using the 12 X-chromosomal STR markers included in the Investigator® Argus X-12 kit (Qiagen). The 12 X-STR markers are located in four linkage groups (linkage group I: DXS10135, DXS10148, and DXS8378; linkage group II: DXS7132, DXS10079, and DXS10074; linkage group III: DXS10103, HPRTB, and DXS10101; and linkage group IV: DXS10146, DXS10134, and DXS7423). Allelic frequencies of the 12 X-STR loci and haplotype frequencies of the four linkage groups were investigated. No significant difference was observed in the allele frequencies of males and females. Distributions of heterozygosity were observed from 64.5 to 92.5% among the studied 12 X STR loci. DXS10135 and DXS10101 loci were found to be most polymorphic. For all the four linkage groups, the haplotype diversity was found to be greater than 0.986. A total of 95, 73, 66, and 74 haplotypes were observed in linkage groups I, II, III, and IV, respectively. Hardy-Weinberg equilibrium tests showed no significant deviation from expected values for all 12 loci (p > 0.05). The exact test for pairwise linkage disequilibrium for the 12 loci in the male samples did not show any significant linkage disequilibrium except the DXS10103 and DXS10101 loci after the p values were corrected by Bonferroni's correction for multiple testing (p > 0.05/66). A combined power of discrimination in male and female individuals were 0.999999998159791 and 0.999999999999993, respectively. The combined mean exclusion chance were 0.999997635 in deficiency cases, 0.999999996 in normal trio cases, and 0.999999178 in duo cases. The currently investigated Bangladeshi population showed significant differences when compared with previously reported X-STR data from other 12 populations. The results of the data analysis indicated that all the loci in the Investigator® Argus X 12 kit were fairly informative and might be useful in forensic application and kinship analysis in Bangladeshi population.

Phylogenetic and forensic studies of the Bangladeshi population using next-generation PowerPlex® Y23 STR marker system.

Haplotype diversity and allele frequencies of 23 Y chromosomal short tandem repeat (STR) loci included in the next-generation PowerPlex® Y23 System were studied in 137 Bangladeshi Bengali males. A total of 134 different haplotypes were observed with a discrimination capacity (DC) of 0.978, indicating a high potential for differentiating between male individuals in this population. The highest allele frequency (0.818) was observed in locus DYS391. Locus DYS385a/b showed the highest gene diversity (0.945) while locus DYS391 showed the lowest gene diversity (0.302). Double alleles were detected in three loci. On the other hand, four null alleles were detected in a single haplotype at DYS448, DYS549, DYS392, and DYS385a/b locus, respectively. The haplotype data is available in the Y chromosome haplotype reference database under accession number YA003445. To understand the genetic diversity of Bangladeshi Bengali population, a pairwise genetic distances (Rst) was calculated by comparing with 23 population studies consisting 4249 haplotypes. The analysis placed the Bangladeshi population along with Indian Tamil and Indo-Pakistani population in a clade separated from the rest.