SYNTHETIC MOLECULE BLOCKS
CAUSE OF MUSCULAR DYSTROPHY

TUCSON, Ariz., July 16, 2009 — Researchers have found a critical key to blocking the cause of myotonic muscular dystrophy by fooling defective genetic material in a discovery that could have major implications for finding a treatment for the disease, the Muscular Dystrophy Association announced today.

They used a synthetic molecule to block disease-causing genetic instructions in cells. 

“Myotonic dystrophy doesn’t follow the usual rules of genetic conditions,” said Charles Thornton, senior author of the study and co-director of the University of Rochester Wellstone Muscular Dystrophy Cooperative Research Center.  The Wellstone Center receives funding from MDA.  The results of the study were published in the July 16 edition of the journal Science.

“The results in lab testing were better than I could have hoped, but these are still early steps.”

There is no cure for myotonic dystrophy and there are no treatments.

 “It’s important because it impacts the molecular underpinning of myotonic dystrophy and is a major step forward in being able to develop treatments for it,” said Dr. Valerie Cwik, MDA Senior Vice President-Research and Medical Director.

Myotonic dystrophy, the most common form of muscular dystrophy,  is caused by mutations that create copying errors in a body’s genetic material during cell division. These flawed genetic instructions can show up in cells throughout the body, causing not only muscle weakness and wasting, but severe heart, brain and eye disorders.

The synthetic molecule Thornton’s team used is called a “morpholino antisense oligonucleotide, CAG25.”  They injected CAG25 into the muscle cells of mice and found that it released proteins held hostage in cells by defective RNA, a byproduct of the flawed genetic instructions. 

The blocked proteins resumed their normal functions and the muscles showed improvement in molecular structure and function.

“What we have now is proof of concept that this general approach for treating myotonic dystrophy is potentially effective,” Thornton said.

“This work shows that we can take our new knowledge about the disease and use it to design customized treatments.”

MDA is the nonprofit health agency dedicated to curing muscular dystrophy, ALS and related diseases by funding worldwide research. The Association also provides comprehensive health care and support services, advocacy and education. The majority of contributions to MDA come from individual donors.

For a related story, see Coming Unglued.