The 34 so-called single nucleotide polymorphisms, or SNPs, represent good candidate genes predisposing people to the non-inherited form of the fatal neurodegenerative disease.
“Although we haven’t located the exact gene responsible for sporadic ALS, our results seriously narrow the search and bring us that much closer to finding what we need to start developing treatments for the disease,?says Bryan J. Traynor, M.D., of the Department of Neurology at The Johns Hopkins University School of Medicine.
ALS, also known as Lou Gehrig’s disease for the legendary Yankee first baseman who succumbed to its paralyzing assault on the nervous system, kills 10,000 Americans a year. An estimated one in 2,000 people is at risk of developing the disease.
Genes behind inherited forms of ALS -- responsible for about only 5 percent of all cases -- were discovered a decade ago, but no genetic roots have previously been found for sporadic ALS, which occurs in people without a family history of the disease.
In the Johns Hopkins study, described in the online version of Lancet Neurology this month, Traynor and his team scanned the entire genome of 276 adult male and female subjects with sporadic ALS and 271 adult male and female subjects with no history of neurological disease.
Researchers used a new technology known as “SNP chips?to analyze all 555,352 SNPs in the genome of each subject. SNP chips are glass slides that resemble computer processor chips. They’re coated with tiny beads that “read?the SNPs scattered throughout the human genome.
The researchers found 34 genetic variants that ALS patients were more likely to have compared to normal individuals without the disease
Source:Johns Hopkins Medical Institutions