Genome-wide Investigation of Population Structure in Myanmar

Myanmar locates in the crossroads of South Asia, Southeast Asia, and East Asia, and is known for high culture diversity in different ethnic groups. It is considered to be important for understanding human evolutionary history and genetic diversity in East Eurasia. However, relatively few studies have examined the population structure and demographic history in Myanmar to date. In this study, we analyzed more than 220,000 genome-wide SNPs in 175 new samples of five ethnic groups from Myanmar and compared them with the published data. Our results showed that the Myanmar population is intricately substructured, with the main observed clusters corresponding roughly to western/northern highlanders (Chin, Naga, and Jingpo) and central/southern lowlanders (Bamar and Rakhine). The gene flow inferred from South Asia has a substantial influence (~11%) on the gene pool of central/southern lowlanders rather than western/northern highlanders. The genetic admixture is dated around 650 years ago. These findings suggest that the genome-wide variation in Myanmar was likely shaped by the linguistic, cultural, and historical changes. To investigate the genetic structure of Myanmer populations, we genotyped 240 samples of four different ethnic groups (i.e. Bamar also Burman, Chin, Naga, and Rakhine) in Myanmar, neighboring Chinese minor ethnic groups (Jingpo), and Africans from Nigeria conducted on Illumina HumanOmniZhongHua-8 BeadChip. Three Africans here were used as out group. Sample type is normal blood. For general population genetics analysis, we filtered out 4 samples for duplication, 2 for wrong gender information, and 56 samples for close genetic relationship (using IBD test). Finally, 175 genetic-independent individuals data were used to reflect the genetic structure of Myanmar.