Objective: We examined the possible influence of G-->T substitution in transcription factor Sp1-binding site in the gene encoding alpha-1 chain of type I collagen on the risk of stress urinary incontinence.
Study design: The study group consisted of 50 women reporting symptoms of stress urinary incontinence. Fifty control subjects were treated for benign gynecological conditions other then stress urinary incontinence. DNA was obtained from peripheral blood leukocytes. The fragment of the first intron of the gene encoding the alpha-1 chain of type I collagen containing the Sp1-binding site was amplified by polymerase chain reaction. The analysis of restriction fragment length polymorphism was performed.
Results: We found association between the GT and TT genotype and stress urinary incontinence (P = .019). The odds ratio for developing stress urinary incontinence is 4.98 (95% confidence interval 1.97 to 12.56) in subjects presenting the GT genotype and 2.23 (95% confidence interval 0.69 to 7.25) for the TT genotype.
Conclusion: The G-T polymorphism at the Sp1 binding site of the gene encoding alpha-1 chain of type 1 collagen is associated with increased risk of stress urinary incontinence in women.