家系Y-STR基因座容差在系谱推断中的应用

Application of Familial Y-STR Haplotype Mismatch Tolerance in Genealogy In⁃ference

目的研究中国汉族家系中Y-STR基因座容差规律,为SNP系谱推断与家系排查联用工作提供家系选择依据。方法选取3个遗传关系清晰的汉族家系,利用YFiler Platinum PCR扩增试剂盒,得到所采男性样本35个Y-STR基因座分型数据,统计分析Y-STR单倍型在世代遗传中的变化及1~7级亲缘关系中的容差。结果各家系突变基因座及突变次数有差异,Y-STR突变具有家系特异性,66.03%的突变发生在快、高速突变基因座。1~7级亲缘对在35个Y-STR基因座上容差在0~5个,最远6步长;在中、慢速突变基因座上容差在0~2个,最远3步长;在快、高速突变基因座上容差在0~3个,最远6步长。结论联合应用SNP系谱推断技术与Y-STR家系排查,0容差及多容差均需考虑。可优先筛查在全部35个Y-STR基因座上0~3个容差且在中、慢速基因座上0~1个容差的家系。差异数符合条件时,步长较远的家系应谨慎排除。同时,应谨慎增加快速突变基因座。

Objective To provide a guideline for genealogy inference and family lineage investigation through a study of the mismatch tolerance distribution of Y-STR loci in Chinese Han male lineage.Methods Three Han lineages with clear genetic relationships were selected.YFiler Platinum PCR amplification Kit was used to obtain the typing data of 35 Y-STR loci in male samples.The variation of Y-STR haplotypes in generation inheritance and the mismatch tolerance at 1-7 kinship levels were statistically analyzed.Results Mutations in Y-STR were family-specific with different mutation loci and numbers of mutation in different lineages.Among all the mutations,66.03%were observed on rap idly and fast mutating loci.At 1-7 kinship levels,the number of mismatch tolerance ranged from 0 to 5 on all 35 Y-STR loci,with a maximum step size of 6.On medium and slow mutant loci,the number of mismatch tolerance ranged from 0 to 2,with a maximum step size of 3;on rapidly and fast mutant loci,the number of mismatch tolerance ranged from 0 to 3,with a maximum step size of 6.Conclusion Combined use of SNP genealogy inference and Y-STR lineage investigation,both 0 and multiple mismatch tolerance need to be considered.Family lineage with 0-3 mismatch tolerance on all 35 Y-STR loci and 0-1 mismatch tolerance on medium and slow loci can be prioritized for screening.When the number of mismatch tolerance is eligible,family lineages with long steps should be carefully excluded.Meanwhile,adding fast mutant loci should also be handled with caution.