Health: WebMD

Dads More Likely To Pass MS To Kids?

July 25, 2006 / 3:48 PM EDT / WebMD

Kids may be more likely to inherit multiple sclerosis (MS) from their fathers than their mothers.

That news, published in today's issue of Neurology, may, at first glance, seem to defy MS statistics. MS is about twice as common in women as in men.

But "fathers with MS tend to have more children who develop MS than do mothers with the disease," says neurologist Brian Weinshenker, M.D., in a Mayo Clinic news release.

Weinshenker helped conduct the new study. He works at the Mayo Clinic College of Medicine in Rochester, Minn., along with fellow researcher and neurologist Orhun Kantarci, M.D.

The findings shouldn't affect how men with MS are counseled about their children's MS risk, Kantarci says in the news release. The study is "primarily of interest to scientists," he explains.

Checking The Family Tree

The researchers studied 441 children in 206 families who had a father or mother with MS. Of those children, 45 definitely had MS.

Children of fathers with MS were about twice as likely to have definite MS as those whose mothers had MS, even after taking MS risk factors into account, the study shows.

Scientists don't know exactly what causes MS. But they suspect a mix of genetic and environmental factors is involved.

The study doesn't pinpoint the reason for the parent-child MS trend. But the researchers have a theory.

"The hypothesis of the study is that men are more resistant to MS, so they need stronger or a larger number of genes in order to develop MS, and then pass these genes to their children," Kantarci says.

The findings need confirmation. Meanwhile, Kantarci puts the odds in perspective with this explanation:

The risk of having MS if you've got a parent with the disease is about 20 times higher than if you don't have a parent with MS. The additional risk of having a father with MS is not sufficient to change patient counseling practices.

More from CBS News