Association of GSTM1 and GSTT1 Deletion Variants with Susceptibility to Behçet’s Disease in a Saudi Population: A Case Control Study

Behçet’s disease (BD) is a chronic multisystem inflammatory disorder in which genetic susceptibility and oxidative stress may contribute to disease pathogenesis. Glutathione S-transferase (GST) enzymes play an important role in cellular antioxidant defense. Deletion variants of the GSTM1 and GSTT1 result in loss of enzyme activity and may influence susceptibility to BD. A case control study was conducted including 79 patients with BD (n = 79) and 100 controls (n = 100) from Saudi Arabia. Genotyping of GSTM1 and GSTT1 deletion variants was performed using multiplex polymerase chain reaction. Genotype frequencies were compared using odds ratios (ORs) and 95% confidence intervals (CIs). The frequency of GSTM1− null genotype was significantly more frequent in BD cases than in controls (OR = 2.11, 95% CI = 1.15–3.85; p = 0.016; adjusted OR = 2.51, 95% CI = 1.24–5.07; p = 0.010; corrected p = 0.021). The GSTT1− null genotype was also more frequent (OR = 3.10, 95% CI = 1.63–5.89; p = 0.001; adjusted OR = 2.25, 95% CI = 1.08–4.68; p = 0.030), although this association did not remain significant after Bonferroni correction (corrected p = 0.060). Combined genotype analysis showed a significant association for GSTM1−/GSTT1− (OR = 6.90, 95% CI = 2.65–17.98; p < 0.001; adjusted OR = 6.35, 95% CI = 1.89–21.35; p = 0.003) compared with the GSTM1+/GSTT1+ genotype, which remained significant after Bonferroni correction (corrected p = 0.008). Stratified analyses did not demonstrate a clear association between GST deletion variants and disease activity or gender. The present study suggests that the GSTM1− genotype and the combined GSTM1−/GSTT1− genotype are significantly associated with susceptibility to BD in the Saudi population, independent of age and sex.