Introduction and hypothesis: A familial tendency has been demonstrated in the etiology of pelvic organ prolapse (POP), but the specific genetic defects have not been identified. Type III collagen is an important factor in the repair of connective tissue, and gene polymorphisms may impair the tensile strength. We hypothesized that polymorphisms in the alpha I chain of the type III collagen protein-encoding gene (COL3A1) pose women at risk for POP.
Methods: In this case-control study, the prevalence of type III collagen polymorphisms was compared in women with and without signs and symptoms of POP.
Results: Two hundred and two POP patients and 102 normal parous controls were included. A homozygous single-nucleotide substitution in the coding region of type III collagen (COL3A1 2209G>A, rs1800255) was identified in 27 (13%) POP patients and three (3%) controls (odds ratio, 5.0; 95% confidence interval, 1.4-17.1).
Conclusions: The probability of POP was higher in women with COL3A1 2209G>A. This polymorphism showed to be a relevant risk factor for POP.