Recently, advancements in human DNA decoding technology allow for the reading of long DNA sequences at once through a method known as "long-read sequencing." This development enables the decoding of complex regions corresponding to about 8% of the human genome that were previously difficult to analyze. However, there has been little systematic research analyzing the unique structural variations in the genomes of Koreans.
A research team led by Kim Seon-young, a principal researcher at the Korea Research Institute of Bioscience and Biotechnology (KRIBB), along with Professor Park Ji-hwan from Ajou University, Professor Kim Jun, and Professor Yeo Min-kyung from Chungnam National University, noted on the 21st that they have created unique genomic data for Koreans and used it to elucidate the mechanisms of human genome evolution, which were previously unknown.
The research team drafted a genomic map based on the genomic data of three Koreans (De novo assembly), and completed individual genomic maps for each parent, resulting in a total of six high-quality genomic maps. Compared to a reference genome centered on the West, they discovered 131,138 deletion variants and 122,461 insertion variants unique to Koreans. Deletions refer to mutations where specific DNA sequences are deleted, while insertions refer to mutations where new DNA fragments are added to existing DNA sequences.
In particular, they discovered 19 large-scale structural variants in the "subtelomere" region at the ends of chromosomes. This area is prone to structural variations due to frequent DNA damage and repair. Of the 19 mutations discovered, 8 were found in common among 2 of the 3 Koreans. This indicates that genetic variation information that occurred in the common ancestor of humanity is preserved in the DNA of Koreans like a fossil.
The research team also examined the traces left by large-scale variants to reveal the mechanisms that created these mutations. They found that single-strand annealing (SSA) and break-induced replication (BIR) mechanisms, which are primarily involved in DNA damage repair processes, were the main causes of the mutations. SSA is a method for simply repairing DNA damage based on repeat sequences, whereas BIR is a mechanism that uses other DNA sequences as templates to replicate and repair significant damage.
Cho Soo-bok, the first author of the paper and a researcher at the Korea Research Institute of Bioscience and Biotechnology, stated, "We have taken a step closer to understanding the unique genetic characteristics of Koreans by utilizing high-quality human genomic sequence information," and asserted, "The 'National Integrated Bio-Big Data Construction Project' will systematically build a large-scale genomic database for Koreans, laying the foundation for Korea to enhance its competitiveness in global genomic research and precision medicine."
The research findings were published in the international journal of genomics, "Nucleic Acids Research," on the 8th.
Reference materials
Nucleic Acids Research (2025), DOI: https://doi.org/10.1093/nar/gkae1294