A consortium of researchers identified a genetic variant that improves survival of individuals with amyotrophic lateral sclerosis (ALS). Reporting in the Proceedings of the National Academy of Sciences, they say that a variant in the KIFAP3 gene was associated with an increase in survival time of 40% to 50%.
Because survival with ALS is normally only three to five years, patients with the KIFAP3 gene variant experience a substantial improvement, according to the investigators. In fact, the impact of this genetic variant is comparable to the effect of the only FDA-approved ALS drug, Rilutek from sanofi-aventis, they add.
The group, which included scientists from the U.S., Mexico, Israel, and Europe examined more than 300,000 genetic variants in over 1,800 people with ALS and nearly 2,200 unaffected controls.
While it's still unclear how the KIFAP3 gene variant alters the progression of ALS, the researchers know that it is involved with a number of cellular processes including the transport of essential molecules throughout the nerve cell.
“The favorable gene variant decreases levels of a motor protein complex in nerves,” explains John Landers, Ph.D., associate professor of neurology and one of the study leaders. “This complex transports substances through different parts of nerve cells.”
“This report is the first to describe genetic factors that determine rate of progression in ALS,” states Robert Brown, M.D., D.Phil., chair and professor of neurology at the University of Massachusetts Medical School, who co-led the research.
In 1993 a team of researchers led by Dr. Brown reportedly discovered the first gene linked to familial ALS, a protein antioxidant known as superoxide dismutase, or SOD1. Earlier this year, Dr. Brown and his colleagues discovered a mutation in the FUS/TLS gene which is estimated to account for 5% of inherited ALS cases. There are only four known genes that, when mutated, cause familial ALS.
Past Research in ALS
Extra Copy of Gene Prolongs Life in Mice with Inherited Form of ALS (Dec. 10, 2008)
Outnumbering Unhealthy Cells with Healthy Ones Helps Sustain Breathing in ALS Mice (Oct. 20, 2008)
Protein Stability and Aggregation Propensity Play a Role in ALS Patient Survival (July 29, 2008)
Scientists Develop Yeast-Based Genetic Screen for Protein Linked to ALS and FTD (Apr. 18, 2008)
Link between Mutation and Inherited ALS Discovered (Feb. 21, 2008)