A recent study conducted by a research group from the RIKEN Center for Integrative Medical Sciences has unveiled the complex genetic makeup of the Japanese population, revealing three distinct ancestral components: Jomon, East Asian, and Northeast Asian. This extensive whole-genome sequencing analysis involved 3,256 samples from Biobank Japan and highlighted that Jomon ancestry is most prevalent in Okinawa (28.5%), followed by Northeastern Japan (19%) and Western Japan (12%). These findings, published on April 18, 2024, provide a deeper understanding of the genetic diversity within Japan, challenging the long-held belief of a homogeneous population.
In addition to ancestry, the study identified clinically relevant genetic variants linked to hereditary breast cancer, including one variant unique to Japanese populations and another shared with China and Korea. The research also uncovered gene sequences from Neanderthals and Denisovans, including variants associated with type 2 diabetes, further emphasizing the health implications of this genetic diversity. Chikashi Terao, the research leader, underscored the study's potential impact on future genetic research and personalized medicine, suggesting that understanding these genetic variations could lead to better health outcomes for the Japanese population.
This research complements earlier findings published on October 10, 2023, by the University of Tokyo, which indicated that modern Japanese people descend from three ancestral groups: the Neolithic Jomon hunter-gatherers, a group believed to be ancient predecessors of Han Chinese, and an unidentified group linked to Northeast Asia. The study revealed substantial genetic differences between regions, suggesting a more intricate genetic landscape than previously understood. The creation of a new database, JEWEL, aims to facilitate future genetic research and further explore these findings. The combined insights from both studies are expected to influence ongoing discussions about the genetic history and health of the Japanese people, prompting a reevaluation of genetic health risks faced by this population.[7d30ef9b][6a97d3ae][a4cbce75]