Study On The Mutations And MRNA Expression Of Perforin Gene In Peripheral Lymphocytes Of The Patients With Severe Acquired Aplastic Anemia

Objective:This study was to investigate the mutations and mRNA expression of perforin gene of the patients with severe aplastic anemia (SAA) and explore the relationship between perforin and the pathgenesis of SAA.Methods:Exon2 and exon3 of perforin gene mutation in Peripheral mononuclear cells of aplastic anemia patients were analysed by DNA direct sequencing, sequences were compared with the Genbank reported reference sequences.The genotype and allele frequency of rs885822 SNP site between SAA patients and normal controls were compared with chi-square test; Perforin mRNA expressing level in Peripheral mononuclear cells of aplastic anemia patients were analysed by reversed-transcript PCR method,and compared with independent t test.Results:822 C>T Homozygous mutation (Synonymous mutation) and 907 G>A Heterozygous mutation (Met303Val) were found in some patients with SAA. Those mutations were not found in normal controls. SNP rs885822 obeyed the Hardy-Weinberg equilibrium,and the genotype and allele frequency were significantly differed between SAA patients and normal controls(P=0.016, P=0.021); There was significant difference of perforin mRNA expressing level in Peripheral mononuclear cells of SAA patients and normal controls of perforin(P=0.048)Conclusion:Gene mutations of perforin were detected in SAA patients.The genotype and allele frequency of SNP rs885822 were significantly differed between normal controls and SAA patients. Perforin gene mutation might be one risk factor in the aberrant proliferation and activation of cytotoxic T cells in the pathogenesis of a part of SAA; Perforin pathway maybe one of the main pathogenesis mechanism that T cells damage hematopoietic stem and progenitor cells in SAA.