Identification of novel SNP markers for kinship analysis in the Korean population

Kinship testing using genetic markers such as short tandem repeats (STRs) and single nucleotide polymorphisms (SNPs) is crucial for forensic analysis. Although STR markers have superior discriminatory power due to their highly polymorphic properties, they have several weak points in determining extended distant or complex relationships because of high mutation rates and low success rates in degraded samples. Therefore, SNPs are regarded as promising tools in forensic science because they have low mutation rates and small amplicon sizes. Herein, we propose an SNP panel consisting of 1400 autosomal SNPs obtained from the Korean National Standard Reference Variome (KoVariome) database. To evaluate its performance, in-silico analysis was performed using whole-genome sequencing (WGS) data from 21 Korean families. Subsequently, to estimate pairwise relatedness, kinship coefficients were calculated using PLINK, and Welch's one-way ANOVA test with Games-Howell's pairwise comparison test was performed. As a result, the average kinship coefficients of first- (parent-offspring and full siblings), second- (grandparent-grandchildren and aunt/uncle-niece/nephew), and third- (first cousin and grandniece/grandnephew) degree relatives, and unrelated were 0.24, 0.11, - 0.054, and - 0.0082, respectively. Consequently, relatives (first and second degree) were distinguished from non-relatives; however, further studies are required to investigate more effective SNP markers for discriminating extended kinship. Nevertheless, the results of this study go beyond the scope of screening using the discovered 1400 SNPs in Korean families and suggest the applicability of kinship analysis in the Korean population.