Association of MMP-9 gene polymorphisms with Behçet's disease risk

• We evaluated the association of 4 SNPs in MMP9 gene with Behçet's disease risk.
• The MMP9 2003 G/A and 836 G/C polymorphisms were associated with BD risk.
• The MMP9 1721 C/G polymorphism was identified as protective factor against BD.
• The MMP9 -1562 C/T polymorphism was not associated with BD risk in Tunisian.

The human matrix metalloproteinases (MMPs) are importantly involved in aneurysm formation. Since the clinical manifestations in Behçet disease (BD) include aneurysm formation among major symptoms, polymorphisms in MMP-9 might be associated with BD susceptibility. The aim of the current case–control study was to investigate the association of four single nucleotide polymorphisms (SNPs) in MMP-9 gene: -1562 C/T, 2003 G/A (R668Q), 836 A/G (Q279R) and 1721 C/G (R574P) with BD risk in the Tunisian population. The distribution of MMP-9 gene polymorphisms was analyzed by polymerase chain-reaction (PCR) and restriction fragment length polymorphism (RFLP) for 240 BD patients and 288 controls. Our study indicated that the MMP-9 -1562 C/T polymorphism (rs3918242) was not associated with BD risk. We found a significant association of the MMP-9 2003 G/A (rs17577) with an increased susceptibility to BD. However, the MMP-9 1721 C/G polymorphism (rs2250889) had a protective role against the development of BD. Subgroup analysis based on stratification by gender revealed that the MMP-9 2003 G/A polymorphism was associated with a highly significant BD risk in women's group (G vs. A: P = 0.0000001). However, the MMP-9 836 A/G polymorphism had a protective role in men's group (G vs. A: P = 0.00043). The MMP-9 1721 C/G polymorphism was associated with a protective effect in both men and women groups (CG + GG vs. CC: P = 0.04 and P = 0.0002, respectively). The haplotype analysis did not show any association with BD risk. A significant difference in the MMP-9 serum levels were observed in the patient subgroup with ocular lesions manifestations.