16个X-STR基因座的连锁不平衡检验和突变率调查

Linkage Disequilibrium and Mutation Rate Analysis of Sixteen X-STR Loci

目的检测X染色体上16个STR基因座的连锁不平衡情况,并对其遗传稳定性进行调查。方法从华东汉族群体选取女性无关个体500名、家系885个,提取血样DNA,利用自主研发的IDtyper X-16试剂盒对16个X-STR基因座进行多重PCR扩增和毛细管电泳分型,使用Power Marker v3.25软件对基因座进行连锁不平衡检验,并分析各个基因座的突变率。结果 16个X-STR基因座彼此之间不存在连锁不平衡现象;有10个基因座检见突变,其中DXS6809和DXS7132的突变率均高达0.004 8。结论对于IDtyper X-16试剂盒中的16个X-STR基因座,在亲权鉴定中应用时可运用乘积原理计算似然率,但若遇到不符合遗传规律的情形(尤其是DXS6809、DXS7132基因座),应考虑存在突变的可能。

Objective To assess the patterns oflinkage disequilibrium （LD ） of16 STR loci on X chrom o-som e and investigate the genetic stability. Methods G enom ic DNA samples extracted from blood stains from 500 unrelated individuals and 885 lineage m em bers from E astern C hinese H an population were genotyped through m ultiplex am plification using ID typerX-16 kit by our independent research followed by capillary electrophoresis. LD was assessed by PowerM arker v3.25 software and m utation rate of every locus was analyzed. Results LD were not found at the 16 X-STR loci. A llele m utations were observed at 10 loci. A m ong them , m utation rates of DXS6809 and DXS7132 were both up to 0.004 8. Conclusion W hen the 16 X-ST R loci included in ID typerX-16 kit were used for parentage testing, product princi-ples can be applied to calculate the likelihood, but m utation should be taken into consideration in the case that the genotypes do not m eet the genetic law（especially at DXS6809 and DXS7132）.