Genes play important role in urinary incontinence

Genetic factors explain half of a person’s susceptibility to urinary incontinence, Swedish researchers report.

"We already knew that there are hereditary factors, but now we’ve been able to show for the first time how important the genetic component is for various types of urinary tract disorders," said first author Anna Lena Wennberg, MD, PhD, of Sahlgrenska Academy, Gothenburg, Sweden.

Conducted in collaboration with the Swedish Twin Registry at Karolinska Institutet in Stockholm, the study looked at more than 25,000 twins aged 20 to 46 years. Information about urinary incontinence, overactive bladder, and other lower urinary tract symptoms were analyzed.

"With urinary incontinence, we saw that just over half of the variation (51%) can be explained by genetic factors," Dr. Wennberg said. "This doesn’t mean that half of all people with urinary incontinence inherit it from their parents, but that around 50% of people’s susceptibility to urinary incontinence can be explained by their genes."

Genes were also significant for nocturia, with around one-third (34%) of the variation pointing to a genetic explanation.

Dr. Wennberg said she does not believe that there is a single incontinence gene, but that a number of different genes play a role. These genes combine with various environmental factors or cause disorders that, in turn, increase the risk of urinary incontinence.

Results from the study were published online in European Urology (March 17, 2011).