Genetic Mutation Linked To Lou Gehrig’s Disease And Dementia

  
Scientists have identified a new human genetic mutation that is responsible for the most common cause of Lou Gehrig’s disease and dementia.
The researchers performed a genetic analysis and determined that a genetic mutation in the gene C9ORF72 was found in almost 12 percent of all dementia patients in the study and over 22 percent in all amyotrophic lateral sclerosis (ALS), or Lou Gehrig’s disease patients.
“This finding has the potential to lead to significant insights into how both of these neurodegenerative diseases develop, and may give us much needed leads into new ways to treat our patients,” senior investigator Rosa Rademakers, Ph.D., a neuroscientist at the Mayo Clinic campus in Florida, said in a press release.
Researchers have found similarities between both dementia and ALS patients.  Dementia is characterized by changes in personality, behavior and language due to loss of gray matter in the brains’ frontal lobe.  ALS destroys motor neuron cells that control muscle activity like speaking, walking, breathing and swelling.
Researchers have found that up to half of ALS patients experience symptoms of dementia and up to half of dementia patients develop symptoms seen in Lou Gehrig’s disease.
Bryan J. Traynor, M.D., an assistant professor in the Department of Neurology at the Johns Hopkins University School of Medicine, and colleagues used a genomic sequencing technique on pieces of chromosome 9 sampled from ALS and dementia patients.
They compared the sequences to healthy people outside of the participants’ families who had never been diagnosed with either condition.
A genetic mutation turned up in a section of chromosome 9 in the C9ORF72 gene in just the affected individuals. 
“If you think of chromosomes like geographic regions, we knew what city this mutation was located in, and what part of the city, but we didn’t know what street it was located on or which house,” Traynor said in a press release. “We were really looking for the exact address for this mutation.”
He said he and his colleagues do not know how the repeated segments might cause ALS and dementia, but it could cause affected cells to manufacture toxic genetic material that clogs up cells and eventually leads to their destruction.
“This finding has the potential to lead to significant insights into how both of these neurodegenerative diseases develop, and may give us much needed leads into new ways to treat our patients,” senior investigator Rosa Rademakers, Ph.D., a neuroscientist at the Mayo Clinic campus in Florida, said in a press release.
Two independent studies were published online regarding this discovery by Cell Press in the journal Neuron. 

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