Treatment neutralizes muscular dystrophy in mice

By Julie Steenhuysen

CHICAGO (Reuters) - U.S. researchers have found a way to block the genetic flaw that causes a common form of muscular dystrophy, the team reported on Thursday.

Mice injected with a compound that neutralizes faulty gene activity regained the use of muscles frozen by myotonic dystrophy, the researchers said.

"We haven't corrected the underlying gene abnormality," said Dr. Charles Thornton of the University of Rochester in New York, whose study appears in the journal Science.

"What we've done is made it behave in a more mannerly fashion," Thornton said in a telephone interview.

The research relies on a technology called antisense, which uses synthetic molecules to block the activity of specific genes. Several companies, including Isis Pharmaceuticals, are developing drugs using this approach.

Thornton said unlike many inherited diseases in which faulty genes make faulty or missing proteins, myotonic dystrophy makes a toxic form of ribonucleic acid or RNA, which carries genetic instructions for making proteins.

In myotonic dystrophy, however, the RNA is toxic to cells, Thornton said.

"This RNA has proteins that get stuck on it," he said.