Resolving the recombination pattern of 38 X-STRs from Chinese Han three-generation pedigrees. (November 2022)

• Record Type: Journal Article
• Authors: Song, Feng; Wei, Xiaowen; Zhou, Chengye; Wang, Shuangshuang; Deng, Chuncao; Liao, Miao; Luo, Haibo
• Is Part Of: Legal medicine. Volume 59(2022)
• Publication Date: 2022-11
• Subjects: Recombination -- Mutation -- X-STR -- Chinese Han -- Three-generation pedigree; Medical jurisprudence -- Periodicals; Forensic Medicine -- Periodicals; Médecine légale -- Périodiques; Medical jurisprudence; Periodicals; 614.1
• DOI: 10.1016/j.legalmed.2022.102135
• Languages: English
• ISSNs: 1344-6223

Abstract

Highlights: Genetic linkage, recombination fractions and mutation of 38 X-STR loci were analyzed in Chinese Han three-generation pedigrees. Twenty-two recombination events were observed within the clusters of closely linked makers spanning < 1.0 Mb. Significant linkage marker pairs were observed with the LOD scores ranged from 2.0104 to 54.8316 which proved that meiotic recombination was not a simple function of physical distance. The average mutation rate for the 38 loci was estimated to be 1.32 × 10 −3 per meiosis. Abstract: X-chromosomal markers have been proved as a useful tool for solving complex kinship cases due to its sex-linked inheriting feature. Among these markers, tightly linked X-STR clusters forming haplotypes are highly informative. The analysis of the haplotypes requires determination of linkage disequilibrium. In this study, genetic linkage, recombination fractions and mutation rates of 38 X-STR loci in 177 three-generation pedigrees were investigated. Genetic linkage analysis and calculation of recombination fractions were performed within each pair of markers and clusters. Then mutation rates were calculated. The results showed that, a) 22 recombination events happened within the tightly linked X-STR clusters, which span<1.0 Mb; b) significantly linked marker pairs were observed with the LOD (logarithm of the odds) scores > 2.0 (2.0104 to 54.8316); c) the average mutation rate of the 38 X-STR loci was 1.32 × 10 −3 per meiosis in the Chinese Han population, with DXS10135 and DXS8377 presenting notably high mutation rate (6.5 × 10 −3 ). Our results confirmed that meiotic recombination was not a simple function of physical distance, so that whether recombination occurred at the closely clustered X-STRs or not should be assumed cautiously considering the stability of haplotypes in inheritance process for kinship analysis. This study supplemented the existing database and laid an experimental foundation for the future study on genetic characteristics, recombination, and mutation of the X-STRs.