Mutational analysis of 3 Glanzmann's thrombasthenia pedigrees / 中华检验医学杂志

ABSTRACT

Objective 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 ITGA2Bc. 814G>C (p. Val272Leu), ITGA2Bc. 432G>A (p. Trp144Ter) and ACTN1c. 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 ITGA2Bc.814G>C (p.VAL272LEU), ITGA2Bc.432G>A (p.Trp144Ter) and ACTN1c.2458A>G (p.Ile820Val) are pathogenic.