D18S51基因座引物结合区碱基突变导致等位基因丢失

Base mutation in primer binding region of D18S51 locus leads to allele loss

目的分析DNA鉴定中D18S51基因座的等位基因丢失现象,探讨其对鉴定结果的影响。方法采用STR复合试剂盒检测,发现D18S51基因座的等位基因丢失,并对该等位基因进行测序分析。结果D18S51基因座丢失的等位基因在序列侧翼引物结合区发生突变,第8个碱基发生A突变为G,导致等位基因丢失的发生。结论在DNA鉴定中等位基因丢失易被误判为突变,需采用不同试剂盒检测验证,必要时加测其他遗传标记,避免累计亲权指数结果的错误。

Objective To analyze the allelic loss of D18S51 locus in DNA identification,and to explore their effects on the identification results.Methods The allele of D18s51 locus was detected by STR complex kit,and the al-lele was sequenced.Results The allele of D18s51 locus was mutated in the primer-binding region of the flanking se-quence,and the 8th base was mutated from A to G,resulting in allelic loss.Conclusion Allelic loss is easy to be mis-judged as mutation in DNA identification.Different kits should be used for detection and verification,and other genetic markers should be added if necessary to avoid the error of cumulative parental index results.