Mutations of ASXL1 gene in myelodysplastic syndromes / 白血病·淋巴瘤

ABSTRACT

Objective To investigate the mutations of epigenetic regulation factor ASXL1 gene in myelodysplastic syndrome(MDS).Methods Mutation analysis of ASXL1 gene in 53 de novo MDS patients and 20 healthy persons was performed by using polymerase chain reaction(PCR)followed by sequence analysis at DNA level.The clinical and laboratory characteristics were compared in MDS patients with ASXL1 gene mutation and ASXL1 wild type.ASXL1 mutation in mRNA level was detected by using reverse transcription PCR(RT-PCR)followed by sequence analysis.Results ASXL1 gene mutations were observed in 9 cases(16.9%)of 53 MDS patients.6 mutation types were detected,including 4 frameshift mutations types(2 cases with p.Glu635ArgfsX15,3 cases with p.Gly646TrpfsX12,1 case with p.Ala640GlyfsX14 and 1 case with p.Gly790TrpfsX10)and 2 nonsense mutation types(1 case with p.Gln1063X and 1 case with p.Gln695X).All the mutations were heterozygous,and p.Gly790TrpfsX10 and p.Gln695X were new mutation types.In addition,a single nucletide polymorphism(SNP)p.Gly652Ser was also detected in 4 cases with MDS.5 cases of p.G652S SNP and 1 case of p.Leu1173Leu SNP were detected in 20 healthy people.Frameshift mutation(p.Gly646TrpfsX12)could be detected at mRNA level by using RT-PCR.Differences were not observed in red blood cell counts,white blood cell counts,platelet counts,hemoglobin levels,reticulocyte,neutrophil granulocyte,the peripheral blood lymphocytes percentage,T-cell subsets in the peripheral blood,the proportion of primitive cell in the marrow and MDS types between the patients with ASXL1 gene mutation and ASXL1 wild type patients(P >0.05).Conclusion There is a high frequency of ASXL1 gene mutation in MDS patients,which can be detected at mRNA level.