MMP 2 , MMP 9 and TIMP 2 polymorphisms affect sperm parameters but not fertility in Polish males

Summary Proper function of the blood–testis barrier is pivotal to spermatogenesis. Synchronised action of matrix metalloproteinases ( MMP ) and their inhibitors ( TIMP ) is mandatory to maintain dynamic balance of the barrier. Therefore, the association of functional genetic variants of MMP ‐2, MMP ‐9 and TIMP ‐2 and male infertility was studied. A total of 416 infertile males and 421 healthy subjects were genotyped for 7 SNP s within MMP 2 , MMP 9 and TIMP 2 genes, along with the assessment of semen parameters (concentration, motility and morphology of spermatozoa). No association was observed between the studied genotypes and male infertility. However, higher sperm concentration was associated with TIMP 2 rs8080623 C and rs2277698 T variants among infertile men, and with MMP 9 rs17576 A minor allele in controls ( p  < .05). TIMP 2 rs9900972 T and rs2277698 T allele were associated with higher percentage of morphologically normal spermatozoa among controls. MMP 2 rs2285053 TT homozygous infertile patients presented higher percentage of spermatozoa displaying nonprogressive motility. Haplotype analysis revealed strong linkage disequilibrium between the studied loci (5 of 8 possible TIMP 2 haplotypes, and 3 of 4 possible MMP 2 and MMP 9 were found). None of the haplotypes showed association with infertility. This study results suggest an association between MMP 9 and TIMP 2 SNP s with sperm parameters, but not infertility.