Association of rs3765459 single nucleotide polymorphism of the CD40 gene with cerebral infarction susceptibility

Objective To determine whether the rs3765459 polymorphism of the CD40 gene is associated with cerebral infarction susceptibility. Methods Two hundred and one cerebral infarction patients who were hospitalized at the Second Hospital of Shanxi Medical University from February 2015 to January 2017 were selected as a case group. A group of 139 healthy people who were hospitalized during the same period were selected as a control group. Genomic DNA samples were extracted from the whole blood using the standard phenol/chloroform protocol. The rs3765459 locus A/G polymorphism of the CD40 gene was genotyped by real-time quantitative polymerase chain reaction-TaqMan probe method. The t-test was used to compare the difference in age between the two groups. Sex, smoking history, drinking history, diabetes history, hyperlipidemia, different genotypes (GG/AG/AA) and alleles (A/G) were compared between the two groups by the χ2 test. The relative risk of allele (A/G) is expressed as the odds ratio (OR) with 95% confidence interval (95%CI). Further stratified analysis was carried out to compare the genotypes and alleles between patients with different types of cerebral infarction and controls, between different sex groups, and between different age groups. Results There were significant differences in age and male cases between the case group and the control group [(64.12±12.65) years vs (56.69±11.82) years, t=71.33, P<0.001; 129 vs 73, χ2=4.634, P<0.031). The frequencies of rs3765459 AA, AG, and GG genotypes were 11.90% (24/201), 37.80% (76/201) and 50.20% (101/201) in the case group, respectively, and 15.10% (21/139), 49.60% (69/139) and 35.30% (49/139) in the control group, respectively. The frequency of GG genotype and G allele in the case group was significantly higher than that in the control group (χ2=7.508, P=0.023). The frequency of G allele in the two groups was 69.20% (278/402) and 60.10% (167/278), respectively, and the difference was statistically significant. The risk of cerebral infarction was increased in G allele carriers (OR=1.490, 95%CI: 1.082-2.052). Stratified analysis showed that GG genotype and G allele frequencies (51.90% and 70.80%, respectively) in the case group were significantly higher than those in the control group (34.2% and 43.2%, respectively). The G/G genotype and G allele frequencies (51.80% and 70.20%, respectively) in patients with atherosclerotic cerebral infarction were significantly higher than those in the control group (35.30% and 60.10%, respectively) (P<0.05). Conclusion The rs3765459 single nucleotide polymorphisms is associated with susceptibility to cerebral infarction, and G allele may be associated with increased risk of cerebral infarction. The genotype distribution of rs3765459 locus is associated with stroke subtype (atherosclerotic cerebral infarction) and gender (male). Key words: Cerebral infarction; rs3765459; Polymorphism, single nucleotide; CD40 gene