Meta-analysis showed a statistical significance between the MTHFR 677 TT genotype and the presence of BD in overall analysis (TT vs. CC: OR = 2.00, 95% CI, 1.30-3.07; TT vs. CT/CC: OR = 1.97, 95% CI, 1.31-2.97, respectively) and Caucasians (TT vs. CT/CC: OR = 1.84, 95% CI, 1.19-2.86). This evidence concerns the gene MTHFR and Behcet disease.