Investigation of X-STR haplotype diversity in the Australian Aboriginal population

ABSTRACT

X-chromosome short tandem repeat (X-STR) analysis complements autosomal and Y-chromosome STR typing for complex kinship analysis and screening of candidate lists in familial searches. To statistically evaluate X-STR profiling results, Australian forensic laboratories require X-STR haplotype frequency databases for relevant populations. Our study is the first to report haplotype data for the Australian Aboriginal population. X-STR haplotypes were generated for 298 self-declared male Aboriginals using the Investigator® Argus X-12 Kit. Haplotype frequencies and parameters of forensic interest are presented. The discrimination power of a full haplotype was 98.7% and the cumulative power of discrimination was 0.9999999988 for males and 0.999999999999999 for females. MDS plots of pairwise F_ST genetic distances and STRUCTURE histograms identified some segregation of X-STR haplotypes between individuals from the Desert and Eyre regions as compared to the Spencer, Riverine and urban Adelaide regions. Comparison of Australian Aboriginal X-STR haplotypes to those of other global populations showed the most similarity to Europeans and least similarity with Asian populations. Ancestral X-STR haplotypes appeared most conserved in the outback Desert and Eyre regions where assimilation with Europeans is lower. Overall genetic structure was minimal and a single X-STR haplotype database combining all regions is considered appropriate for likelihood ratio calculation.

KEYWORDS:

• Australian aboriginal
• X chromosome
• X-STR
• argus X-12 QS kit
• haplotype data
• population genetics

Acknowledgments

We thank QIAGEN for supplying the Investigator® Argus X-12 QS Kits and for technical assistance. We also thank staff of the Forensic DNA Analysis group at Forensic Science SA for laboratory assistance.

Disclosure statement

No potential conflict of interest was reported by the author(s).