10.Screening of 30 microhaplotype genetic markers withlow recombination rates

Abstract:

The cost and reliability of paternity testing are strongly dependent on the type of DNA genetic marker used． Microhaplotypegenetic markers，characterized by high polymorphism and low mutation rates，have attrcated considerable attentions in forensic evidenceanalysis． However，the impact of meiotic recombination between homologous chromosomes during gamete production on microhaplotypemarker-based paternity testing remains largely unknown． This study utilized SNP data from the 1 000 Genomes Project and a high-reso-lution recombination rate map to screen microhaplotype markers composed of binary SNPs with extremely low recombination rates． A30-microhaplotype genetic marker system was established and its forensic applicability was evaluated． The results show that ( 1) recom-bination rates significantly affect the forensic parameters of microhaplotypes，with low recombination rate microhaplotypes being moresuitable for paternity testing; ( 2) the Cumulative Power of Discrimination ( CPD) and Cumulative Probability of Exclusion ( CPE) of the established microhaplotype system are 99． 999999999999999999999999999999999643% and 99． 9999999999547% ，respectively，surpassing existing microhaplotype marker systems; ( 3) a formula for calculating the paternity index of microhaplotype markers consid-ering mutation has been proposed． Peer researchers can use it to calculate the paternity index of microhaplotype markers quickly andconveniently; ( 4) additionally，based on our results，a microhaplotype database ( http: / /123． 249． 22． 247: 8080 / ) has been devel-oped for searching and analyzing microhaplotypes． These findings can provide valuable guidance on mitigating the negative impact of re-combination rates on paternity testing genetic marker systems，thereby enhancing their accuracy and reliability．

Keywords: haplotype; probability of exclusion; meiotic recombination; SNP