Limb-Girdle Muscular Dystrophy (LGMD)
Throughout the 1990s and the first decade of the 21st century, MDA-supported researchers identified dozens of genes that, when defective, cause LGMD.
This gene identification work continues to the present day, along with research to determine the precise function of these genes so that missing functions can be compensated for and toxic functions can be inhibited.
In the recessive forms of LGMD, it may be possible to insert a new gene to compensate for one that isn’t working properly. This type of intervention — gene therapy — has shown promise in a pilot trial in people with the alpha-sarcoglycan-deficient form of LGMD.
In the dominant forms of LGMD, blocking a toxic function using strategies such as "antisense," which keep cells from interpreting genetic information, may become a treatment in the future.
Some genetic mutations, known as “premature stop codons,” cause cells to stop reading genetic instructions before a fully functional protein has been synthesized. A drug that causes cells to “read through” these stop codons is being tested in another form of muscular dystrophy (Duchenne) and may have some application in LGMD.
Some genetic mutations add or remove DNA and change the way cells interpret the information in a gene. In Duchenne muscular dystrophy, clinical trials are under way of compounds that coax cells to snip out these error-containing DNA regions (exon skipping); this research also may have relevance for LGMD treatment.
Still another strategy is to use stem cells to help ailing muscles regain strength. Stem cells are early-stage, flexible cells that can give rise to mature muscle fibers. They're found in muscle tissue and other places in the body, and scientists are working to determine which cells are the safest and most effective to test in people with LGMD and other diseases.
An additional avenue of investigation is blocking a natural protein called myostatin, which puts a brake on muscle growth.
To read the most current news about any of the research strategies mentioned here, use the MDA search box found at the top of this page.
To learn more, read In Focus: Limb-Girdle Muscular Dystrophy (October 2013 special report).