The effect of a 18 bp deletion/insertion variant of VEGF gene on the FMF development

Objective: Familial Mediterranean fever (FMF) is one of the most common inherited autoinflammatory diseases. Angiogenesis is a feature of inflammatory activation and part of pathogenic processes in autoimmune diseases. Therefore, this study aimed to investigate the role of the Vascular endothelial growth factor (VEGF) gene insertion/deletion (I/D) functional variant in FMF Turkish patients. Methods: MEFV gene mutations were detected in all patients. The FMF patients (N:105) and the healthy controls (N:100) were genotyped for the VEGF I/D variant using PCR followed by agarose gel electrophoresis. The results were statistically analyzed by calculating the odds ratios (OR) and their 95% confidence intervals (95% CI) using the χ²-tests. Results: The mean age of patients was 25.46 ± 10.09. Fifty-nine patients (56.2%) had two or more MEFV gene mutations. The most common MEFV mutation was M694V/M694V. The VEGF I/D variant genotype distribution exhibited a statistically significant difference between the patients and the controls. VEGF I/D genotype was higher in controls compared to patients, while D/D genotype was higher in patients compared to the controls (p = 0.003, p = 0.013, respectively). When we examined the clinical findings, joint pain was more common in patients with VEGF D/D and I/D genotypes compared to I/I genotype (p = 0.043). Although not statistically significant, the most common genotype in patients with two or more MEFV mutations was VEGF D/D (28.6%). Conclusion: The results provided evidence supporting that the D/D genotype of the VEGF I/D variant is associated with an increased risk of FMF in a group of Turkish populations.