Haplotype analysis of the matrix metalloproteinase-9 gene associated with advanced-stage endometriosis

ObjectiveTo investigate whether the −1562C>T, R279Q, P574R, and R668Q polymorphisms of the matrix metalloproteinase-9 (MMP-9) gene are related to endometriosis.DesignCase-control study.SettingUniversity-based hospital in Korea.Patient(s)Patients with endometriosis stage III/IV (n = 225) who underwent pelvic surgery and controls (n = 198) with no endometriosis in a Korean population.Intervention(s)Peripheral blood samples were collected by venipuncture.Main Outcome Measure(s)Frequencies of genotypes and haplotypes were compared with the risk of endometriosis including −1562C>T, R279Q, P574R, and R668Q polymorphisms of MMP-9.Result(s)In the two-locus haplotype analyses using the four single nucleotide polymorphisms (SNPs), an increase in the distribution of the R279Q/P574R (2678G>A/4859C>G) (AC haplotype: odds ratio [OR] = 3.180, 95% confidence interval [CI] = 1.956–5.170; GG haplotype: OR = 4.374, 95% CI = 2.376-8.053) and −1562C>T/R668Q (−1562C>T/5546G>A) (CA haplotype: OR = 3.280, 95% CI = 1.406–7.653) haplotypes was significantly associated with endometriosis. By contrast, the risk of endometriosis was not associated with the individual SNPs studied.Conclusion(s)These findings suggest that haplotype analysis was more informative than SNP analysis. The haplotypes in the MMP-9 gene may correlate with the progression of endometriosis, and further study of these variations might improve our understanding of the pathogenesis of endometriosis.