Purpose: Urinary incontinence and fecal incontinence are common disorders in women that negatively impact quality of life. In addition to known health and lifestyle risk factors, genetics may have a role in continence. Identification of genetic variants associated with urinary incontinence and fecal incontinence could result in a better understanding of etiologic pathways, and new interventions and treatments.
Materials and methods: We previously generated genome-wide single nucleotide polymorphism data from Nurses' Health Studies participants. The participants provided longitudinal urinary incontinence and fecal incontinence information via questionnaires. Cases of urinary incontinence (6,120) had at least weekly urinary incontinence reported on a majority of questionnaires (3 or 4 across 12 to 16 years) while controls (4,811) consistently had little to no urinary incontinence reported. We classified cases of urinary incontinence in women into stress (1,809), urgency (1,942) and mixed (2,036) subtypes. Cases of fecal incontinence (4,247) had at least monthly fecal incontinence reported on a majority of questionnaires while controls (11,634) consistently had no fecal incontinence reported. We performed a genome-wide association study for each incontinence outcome.
Results: We identified 8 single nucleotide polymorphisms significantly associated (p <5×10-8) with urinary incontinence located in 2 loci, chromosomes 8q23.3 and 1p32.2. There were no genome-wide significant findings for the urinary incontinence subtype analyses. However, the significant associations for overall urinary incontinence were stronger for the urgency and mixed subtypes than for stress. While no single nucleotide polymorphism reached genome-wide significance for fecal incontinence, 4 single nucleotide polymorphisms had p <10-6.
Conclusions: Few studies have collected genetic data and detailed urinary incontinence and fecal incontinence information. This genome-wide association study provides initial evidence of genetic associations for urinary incontinence and merits further research to replicate our findings and identify additional risk variants.
Keywords: fecal incontinence; genome-wide association study; urinary incontinence.