A team of researchers at the Mayo Clinic in Jacksonville, Florida, has discovered a new disease mechanism in the C9orf72 gene, which is the most common genetic type of amyotrophic lateral sclerosis (ALS).
ALS, a progressive neurodegenerative disease, harms the nerve cells located in the spinal cord and brain. People who have ALS gradually lose their ability to control muscle movement. This can cause complete paralysis. Death typically occurs between two and five years after the diagnosis. Scientists have not yet discovered why veterans have twice as much likelihood of developing the disease as the general public.
Approximately 40 percent of familial ALS happens because of expansion mutations involving the C9orf72 gene. Six percent of sporadic ALS cases are caused by mutations in this gene, as well as a few frontotemporal dementia (FTD) cases. Researchers have not yet discovered the reason for the gene when it is functioning normally.
When the gene mutates, it has unusually long molecules of RNA, which cause an increase in dipeptide repeat proteins (DPRs). When the gene has too many DPRs, neurons in the brain begin to degenerate. This causes failure in motor and cognitive skills, similar to those in ALS and FTD.
As of today, there is not a cure for the disease. The U.S. Food and Drug Administration (FDA) has approved just one drug, which only modestly lengthens the patients’ survival times.
“This important study provides new data to enhance our understanding of C9orf72-related ALS,” ALS Association Chief Scientist Lucie Bruijn said. “The identification of this new disease mechanism will allow us to determine whether blocking the interaction between DPRs and HR23 may provide a new avenue for treatment development.”