VWA基因座在一个三代家系发生的两次突变

目的探讨短串联重复序列遗传变异的方式。方法用Identifiler^TM试剂盒和DNATyper15^TM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。

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

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.