PowerPlex^TM16体系OL等位基因序列分析及命名探讨

目的观察中国汉族人群PowerPlexTM16体系STR基因座分型标准物外等位基因(OL等位基因)的序列组成,探讨其类型及命名。方法应用PowerPlexTM16体系和ABI377或3100遗传分析仪,对10071名中国汉族无关个体的血样DNA进行15个STR基因座的分型,筛选出OL等位基因样本;对该样本进行单基因座扩增、聚丙稀酰胺凝胶电泳、银染显色,获取等位基因条带并再次扩增和测序。结果在11个基因座检见OL等位基因,共32个,频率0.05‰￣4.02‰,各基因座OL等位基因数目1￣9个不等。按其组成分为四类:(1)重复单位完整重复,但重复次数在ladder范围外;(2)不完整重复;(3)侧翼序列个别碱基的插入或缺失;(4)较大片断的缺失。结论OL等位基因类型不一,既有重复次数的变化,也有侧翼序列或核心序列的变化,现有命名原则尚不能反映其组成类型。

Sequences of off-ladder alleles of PowerPlex 16 kit in Chinese Han population

OBJECTIVE: To study the sequences of off-ladder alleles of PowerPlex 16 kit in Chinese Han population and their nomenclature. METHODS: 10071 Samples from unrelated individuals in Chinese Han population were screened by using PowerPlex 16 kit and ABI 377 or 3100. The samples showing off-ladder alleles were re-screened with PAGE and the off-ladder alleles were obtained and sequenced. RESULTS: 32 off-ladder alleles were found in 11 STR loci, whose frequencies ranged from 0.05 per thousand to 4.02 per thousand. These alleles were classified as four types: (1) having complete repeat but its length is out of the ladder; (2)having incomplete repeat; (3) having deletion or insertion of one or two base(s) in flanking sequence; (4) having deletion of some segment. CONCLUSION: Off-ladder alleles have various types. It demonstrates varying repteating number of the core unit, and variation in the flanking sequence or core sequence as well. The nomenclature of International Society for Forensic Haemogenetics cannot define these alleles effectively.