Association between a single-nucleotide polymorphism of the angiotensin-converting enzyme gene and susceptibility to systemic lupus erythematosus in the Hainanese population of China

The angiotensin-converting enzyme (ACE) gene plays a significant role in regulating immune responses and inflammatory processes, thus impacting the susceptibility to systemic lupus erythematosus (SLE). Understanding how single-nucleotide polymorphisms (SNPs) within the ACE gene contribute to the genetic susceptibility to SLE is essential for comprehending the disease's aetiology. Therefore, exploring this relationship in the Hainan region of China is crucial for gaining insights into the pathogenesis of SLE. This study comprised 428 participants, including 214 SLE patients and 214 healthy controls. Clinical data were gathered, and blood samples were collected. Genotyping of three SNPs (rs4459609, rs4309, rs1987692) within the ACE gene was performed using SNaPshot technology. The frequencies of alleles and genotypes of these three SNPs were compared between the SLE and control groups. Combining different genetic models and haplotype analysis, the correlation between ACE gene polymorphisms and SLE was investigated. Both study groups exhibited conformity with the Hardy–Weinberg genetic equilibrium (p > .05). Significant differences were observed in the genotype frequency distributions of ACE genes rs4459609, rs4309 and rs1987692 between the SLE and control groups (p = .009, .008, .032, respectively). The frequency of allele T at rs4309 was significantly higher in the SLE group than in the control group, correlating significantly with increased SLE risk (odds ratio [OR] = 1.527, 95% confidence interval [CI] = 1.147–2.035). Associations among ACE rs4459609, rs4309 and rs1987692 polymorphisms and increased susceptibility to SLE were found under co-dominant and dominant models (p < .05, with OR values and 95% CI greater than 1). Linkage disequilibrium was observed among rs4459609, rs4309 and rs1987692, and haplotype analysis revealed a significantly higher frequency of the CCA haplotype in the control group compared to the SLE group (p < .001). The ACA and ATA haplotypes showed significantly higher frequencies in the SLE group than in the control group (p = .014, p = .013, respectively). ACE gene polymorphisms are associated with the genetic susceptibility to SLE. The AC and AA genotypes at the rs4459609 locus, the TT genotype and T allele at the rs4309 locus and the AC and CC genotypes at the rs1987692 locus may serve as risk factors for the development of SLE.