['FBLN5 encodes a key protein of elastic fiber matrix assembly and function that contributes to maintaining pelvic support and plays the important role in the pathophysiology of pelvic organ prolapse (POP). The aim of the study was to investigate whether there is an association between common single-nucleotide polymorphisms (SNPs) of the FBLN5 gene and POP.', 'A total of eleven tag SNPs of the FBLN5 gene were genotyped using the polymerase chain reaction with confronting two-pair primers (PCR-CTPP) in 210 patients with POP (stages III-IV) and 292 controls with no even minimal POP.', 'We revealed significant associations of tag SNPs rs2018736 and rs12589592 with POP. The top association signal was found for SNP rs2018736 (protective effect for the minor allele A) in the entire set: p=0.0026, OR=0.42, 95% CI: 0.24-0.75; in the stratum with pelvic floor trauma: p=0.0018, OR=0.27, 95% CI: 0.11-0.64; and in the stratum with fetal macrosomia: p=0.013, OR=0.14, 95% CI: 0.03-0.71. The results of the haplotype analyses were consistent with the single SNP analysis. In the strata without perineal trauma and fetal macrosomia effects were non-significant, possibly, due to the smaller effect sizes.'] Is fibulin-5 ( FBLN5 ) gene polymorphism associated with pelvic organ prolapse?