摘要目的 运用生物信息学软件探讨3个遗传性血小板无力症家系的分子发病机制,为体外实验提供依据.方法对3个确诊遗传性血小板无力症家系进行基因分析.采用ClustalX-2.1-win软件分析突变位点同源序列保守性;采用PolyPhen-2、PROVEAN、SIFT、MutationTaster等软件分析突变位点危害性;采用spdbv软件构建突变蛋白结构模型,分析突变位点对蛋白质结构影响.结果3个血小板无力症家系发现"新突变"为ITGA2B:c.814G>C(p.Val272Leu)、ITGA2B:c.432G>A(p.Trp144Ter)及ACTN1:c.2458A>G(p.Ile820Val).3个突变位点均在同源物种间高度保守.MutationTaster预测结果显示3个新突变均有可能致病,PolyPhen-2和PROVEAN预测结果显示ITGA2B p.Val272Leu、ACTN1 p.Ile820Val为良性的,SIFT预测结果显示ITGA2B p.Val272Leu为有害的,而ACTN1 p.Ile820Val为良性的.突变蛋白质结构分析显示ITGA2B Val272突变为Leu后,原有氢键全部消失.ITGA2B Trp144突变为Ter后形成仅剩113个氨基酸残基的截短蛋白.2个突变均引起GPⅡb分子结构改变,导致GPⅡb/Ⅲa表达减低.ACTN1 Ile820突变为Val后,仅保留Ile820与Asp822的氢键,其余氢键消失,引起ACTN1分子结构改变,影响蛋白质功能.结论ITGA2B:c.814G>C(p.Val272Leu)、ITGA2B:c.432G>A(p.Trp144Ter)、ACTN1:c.2458A>G(p.Ile820Val)突变均有较高的致病可能性.

abstractsObjective To explore the molecular pathogenesis of 3 Glanzmann's thrombasthenia pedigree by using bioinformatics software and provide evidence for in vitro experiments. Methods The genetic analysis of 3 pedigree diagnosed as Glanzmann's thrombasthenia was carried out. Clustalx-2.1 win software was used to analyze the conservatism of mutant sites in homologous sequences. Bioinformatics software such as PolyPhen-2, PROVEAN, SIFT and Mutationtaster was used to analyze the biological effect of mutation. SPDBV software constructed the molecular structure model of mutant protein and evaluated the influence of mutation on protein structure. Results The "new mutations" found in 3 Glanzmann's thrombasthenia pedigree were ITGA2B:c. 814G>C (p. Val272Leu), ITGA2B:c. 432G>A (p. Trp144Ter) and ACTN1:c. 2458A>G (p. Ile820Val). All three mutations were highly conserved among homologous species. Mutationtaster software showed that 3 new mutations were likely pathogenic. PolyPhen-2 and PROVEAN software showed ITGA2B p.Val272Leu and ACTN1 p.Ile820Val were benign and SIFT software showed that ITGA2B p. Val272Leu were likely pathogenic, while ACTN1 p. Ile820Val is benign. The result of SPDBV software showed that the Val272 of ITGA2B was transformed to Leu, neutralizing all the original hydrogen bond. The Trp144 of ITGA2B is transformed to Ter, resulting in the truncated proteins with only 113 amino acid residues. All these mutations affected the molecular structure of GPⅡb, resulting in a decrease ofGPⅡb/Ⅲa expression. When the Ile820 of ACTN1 is transformed to Val, onlyretained the hydrogen bond of Ile820 and Asp822, neutralized the rest hydrogen bond, whichaffected the molecular structure and protein function of ACTN1. Conclusion The mutations of ITGA2B:c.814G>C (p.VAL272LEU), ITGA2B:c.432G>A (p.Trp144Ter) and ACTN1:c.2458A>G (p.Ile820Val) are pathogenic.