Statistical evidence to support the utilization of 21 autosomal short tandem repeats loci for human identification in Malaysian populations

Abstract

The use of 21 autosomal STRs loci for human identification has been gaining popularity throughout the world, attributable to its presumably better statistical discrimination ability. It has been indicated that the forensic statistical parameters for supporting the use of 21 STRs loci varied among the different populations, and such data for the diverse Malaysian populations remain unreported, rendering doubts in the court of law about its real ability for human identification for Malaysian population. Using the GlobalFilerTM Express PCR Amplification kit, the complete DNA profiles of 21 STRs loci from buccal swabs of convicted Malaysian criminal (n = 570; 190 each for Malays, Chinese and Indians) (2016 – 2017) were analysed for their allele frequencies, exact test of Hardy-Weinberg equilibrium, observed and expected heterozygosity, power of discrimination, power of exclusion, match probability and polymorphism information content. Being the most informative locus, SE33 demonstrated the highest power of discrimination and power of exclusion, indicating it usefulness to discriminate individuals. In contrast, TPOX had the lowest power of discrimination and power of exclusion, as well as being the less informative genetic locus for all Malaysian population studied here. The probabilities that two individuals would share the same DNA profiles among the Malaysian Malays, Chinese and Indians, as well as in general Malaysian population were 1.3713 x 10-25, 2.8822 x 10-25, 7.5668 x 10-26 and 1.0385 x 10-26, respectively. The results obtained here were found comparable with similar studies reported in other populations, hence, its robustness for forensic human identification among the Malaysian populations is therefore, statistically supported. Phylogenetic analysis was performed to determine the genetic relationship of the Malaysian population with other Asian populations.