Bed-Wetting Tied to a Faulty Gene, Researchers Say

Scientists say they’ve found the approximate location of a gene for persistent bed-wetting in children.

It’s the first study to show that the problem can be caused by a single gene, said researcher Hans Eiberg. About 8% of 7-year-olds wet their beds at least three times a week without ever having had control over the problem. This is the pattern scientists studied in children past their seventh birthday.

The gene might be responsible for about half to three-quarters of such cases when bed-wetting runs in the family, said Eiberg, a biochemist at the University of Copenhagen’s Institute of Medical Biochemistry and Genetics in Denmark.

Bed-wetting disappears without any treatment in about 15% of affected children each year, and only rarely persists into adulthood. Current treatments for children include medications and an alarm device that wakes the child when the bed is wet.

Finding the bed-wetting gene might help scientists devise new treatments and lead to help in matching children to appropriate treatments, Eiberg said.

He and colleagues report the work in the July issue of the journal Nature Genetics. The study dealt with persistent bed-wetters, rather than children who had been dry for at least six months but then started to wet the bed again.

Dr. George Kaplan, chief of pediatric urology at the UC San Diego, said persistent bed-wetting has long been known to run in families. But the new work is the first he knows of that tried to link it directly to a gene, he said.

“It does demonstrate pretty well that bed-wetting is an inherited trait, at least in some cases,” and that it runs in families because of a gene rather than some parental practice, such as the way the child is toilet-trained, he said.

Eiberg and colleagues studied 11 families with cases of persistent bed-wetting. The pattern through generations suggested that a single gene was at work.

They then analyzed genetic material from five families. By tracking the inheritance of signposts on chromosomes, the microscopic threads that carry genes, the researchers found evidence for a bed-wetting gene in a particular region of the chromosome known as number 13.