Study on the association between matrix metalloproteinase-7 and matrix metalloproteinase-9 promoter single nucleotide polymorphism and the risk of endometriosis

Objective To investigate the association of single nucleotide polymorphism (SNP) in the matrix metalloproteinase-7(MM-7)and matrix metall oproteinase-9(MM-9) promoter with the susceptibility to endometriosis. Methods The SNP of the MMP-7 and MMP-9 gene promoter region was genotyped by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) in 143 endometriosis patients and 160 unrelated healthy women. Results The G allele frequency of MMP-7 among endometriosis was significantly different from the control group (X2=6.59, P=0.01). The genotype frequencies of A/A,A/G,G/G in the case were 86.0%,13.3% ,0.7%, respectively which were significantly different from that of healthy controls(94.4%,5.6%,0% ) (X2=6.50, P=0.039).When comparing it to the A/A genotype, the risk of endometriosis was significantly modified for the G allele carriers with a adjusted odds ratio of 2.71(95% CI:1.19-6.16). The frequency of the C and T allele among endometriosis patients and healthy controls were 88.8% ,11.2% and 91.9% ,8.1%,respectively. No significant difference in MMP-9 allele distribution was shown between the cases and the controls(X2=1.64, P=0.20) nor the significant difference of genotype distribution observed between endometriosis patients and healthy women (X2=2.31,P=0.32). When comparing with the C/C genotype, the risk of endometriosis was not significantly modified for carriers of the T allele and the adjusted odds ratio was 1.41 (95% CI:0.79-2.52). Conclusion Individuals carrying MMP-7 G allele could significantly increase the risk of endometriosis but MMP-9 promoter SNP was not associated with the risk of endometriosis.