Recently, MDA grantee Howard Worman at Columbia University, and colleagues, published encouraging results about the effects of a drug called selumetinib on the hearts of mice with a genetic mutation that's found in a form of Emery-Dreifuss muscular dystrophy (EDMD).
In an approximately 11-minute podcast available now, Worman discusses the reasoning behind testing selumetinib in EDMD mice and his plan to carry this drug, or one like it, into clinical trials.
The lamin A/C gene codes for a protein present in an "envelope" that surrounds the nucleus in most cells.
Mutations in the lamin A/C gene can cause one type of EDMD or the type 1B form of LGMD (LGMD1B). The two diseases can sometimes be found in the same family.
EDMD mainly involves weakness of the skeletal muscles around the shoulder blades and in the lower leg, as well as heart abnormalities; and LGMD1B involves weakness of the muscles close to the body's center (the proximal muscles), as well as heart abnormalities.
The effects of a lamin A/C mutation on the heart are common to both diseases and also can exist without skeletal muscle disease. (Some people with a lamin A/C mutation have little or no skeletal muscle involvement.)
Defects in the lamin A/C protein lead to impairment of the heart's pumping ability (cardiomyopathy), as well as to impairment of signal conduction through the heart, causing dangerously slow or fast heart rhythms. These are the most serious aspects of EDMD and LGMD1B.