MDA awarded a grant totaling $345,000 to Jean-Pierre Julien, professor at Laval University, Canada, for research into genetic variations in a protein called chromogranin B (CHGB) that has been shown to modify disease risk and hasten onset in a type of familial ALS (amyotrophic lateral sclerosis, or Lou Gehrig's disease).
In previous studies, Julien's group discovered that CHGB interacts with mutant, or flawed, forms of the superoxide dismutase 1 (SOD1) protein associated with SOD1-mediated familial, or inherited, ALS.
The team studied variations in the chromogranin B gene, which carries the instructions for the CHGB protein, in a large group of people with and without ALS. Results showed that people with ALS were twice as likely to have a common CHGB variant called P413L than those without the disease. The P413L CHGB variant also correlated with a 2.2-fold greater relative risk for development of ALS, and among those with the disease, onset of symptoms occurred an average 10 years earlier for those with the variant than for those without it.
In its new work, Julien's group will conduct experiments in cultured nerve cells and in a strain of mice engineered to carry the human CHGB variant to test the hypothesis that P413L increases vulnerability of motor neurons. The investigators also aim to determine whether the variant affects CHGB's interaction with mutant SOD1 and uncover the exact mechanism by which it increases risk of ALS and modifies disease onset.
"MDA funding is timely and needed," Julien said, "to determine how this particular genetic variant increases risk of ALS and hastens disease onset."
Funding for this MDA grant began August 1, 2010.