Under the name of "Lua": revisiting genetic heterogeneity and population ancestry of Austroasiatic speakers in northern Thailand through genomic analysis.

Background: Austroasiatic (AA)-speaking populations in northern Thailand are of significant interest due to their status as indigenous descendants and their location at the crossroads of AA prehistoric distribution across Southern China, the Indian Subcontinent, and Mainland Southeast Asia. However, the complexity of ethnic identification can result in inaccuracies regarding the origin and migration history of these populations. To address this, we have conducted a genome-wide SNP analysis of 89 individuals from two Lavue and three Lwa-endonym populations. We then combined our outcomes with previously published data to elucidate the genetic diversity and clustering of AA groups in northern Thailand.

Results: Our findings align with existing linguistic classifications, revealing different genetic compositions among the three branches of the Mon-Khmer subfamily within the AA family: Monic, Khmuic, and Palaungic. Although the term "Lua" ethnicity is confusingly used to identify ethnic groups belonging to both Khmuic and Palaungic branches, our genomic data indicate that the Khmuic-speaking Lua living on the eastern side of the region are relatively distant from the Palaungic-speaking Lavue and Lwa populations living on the western side. The Lavue populations, primarily inhabiting mountainous areas, exhibit a genetic makeup unique to the AA family, with a close genetic relationship to the Karenic subgroup of the Sino-Tibetan language family. Conversely, the Lwa and Blang populations, residing in lowland river valleys, display genetic signatures resulting from admixture with Tai-Kadai-speaking ethnic groups.

Conclusion: Utilizing genome-wide SNP markers, our findings indicate genetic heterogeneity among the Lua, Lavue, and Lwa ethnic groups. The intricate interplay of genetics, cultural heritage, and historical influences has shaped these ethnic communities. Our study underscores the importance of accurate ethnic classifications, emphasizing the use of self-identified endonyms, names created and used by the ethnic groups themselves. This approach respects the AA communities in northern Thailand and acknowledges their significant contributions to advancing our understanding of genetic anthropology.