VWA基因座在一个三代家系发生的两次突变

The observation of VWA mutation twice in three generations of one family

目的探讨短串联重复序列遗传变异的方式。方法用IdentifilerTM试剂盒和DNATyper15TM试剂盒进行检测,用变性聚丙烯酰胺凝胶电泳法对VWA基因座突变家系中3代父、母、子的DNA样本进行STR基因分型,将需测序的等位基因条带从凝胶上切下,再进行PCR扩增,产物经纯化后进行测序。结果此3代家系中Ⅱ-7、Ⅲ-8发生等位基因变异表现为一个重复单位的增加或减少。其中Ⅱ-7的一条发生突变的等位基因具体来源可知,Ⅲ-8的一条突变等位基因无法确定。结论本文中VWA基因座等位基因突变主要表现为一个重复单位的增加,没有碱基的插入或缺失,突变主要来自父亲,突变等位基因无TCTA(TCTG)3(TCTA)n、TCTA(TCTG)5-6(TCTA)n突变类型,均为TCTA(TCTG)4(TCTA)n型突变。

Objective To observe the mutational pattern of STR loci.Methods Samples from three generations of one family were detected by IdentifilerTM Kit and DNA Typer15 Kit.The DNA samples of parent-child pairs with mutations in VWA loci were genotyped by polyacrylamide gel electropheresis on STR.Alleles to be sequenced were excised from gels,reamplified by PCR,and purified.Results There were Ⅱ-7、Ⅲ-8 from parent-child pairs in which the mutation alleles gained or lost a single repeat.The allele mutation of Ⅱ-7 was certain,the allele mutation of Ⅲ-8 was uncertain.Conclusion The mutation of VWA showed single-step mutation event,There was no insertion or deletion of an incomplete repeat.The mutation mainly came from fathers.The type of mutation was TCTA（TCTG）4（TCTA）n,not the type of（TCTG）3（TCTA）n、TCTA（TCTG）5-6（TCTA）n.