Scientists are narrowing in on two regions of the human genome that could be responsible for ALS (amyotrophic lateral sclerosis), also known as Lou Gehrig’s disease.ALS is a neurodegenerative disorder that weakens muscles and paralyzes patients within three years of onset, and has no known cure. The available drug treatment delays progression by only three to five months.Despite several attempts to find genetic variations associated with the sporadic form of the disease (which accounts for 95% of ALS cases), no association has been found.A team of researchers from Netherlands, Van Es et al., analyzed the genes of nearly 20,000 people of European descent, including 5,000 ALS patients. Their results, published online this week in Nature Genetics, identified several genetic variations on two chromosomes suspected to affect ALS and other neurological functions.The study revealed that each copy of the C version of rs12608932, a SNP on chromosome 19, is associated with a 1.2 times increased odds of ALS compared to having two copies of A. This SNP is found near UNC13A, a gene that may be involved in the function of motor neurons, which degenerate and die in ALS patients.Each copy of the T version SNP rs2814707, located on chromosome 9, is associated with a 1.16 times increased odds of ALS compared to having two copies of C. This SNP was found in a region of the genome previously associated with the rare familial (non-sporadic) version of ALS. Researchers also found an association between the disease and a third SNP located very close to rs2814707.(23andMe customers can check their data for rs12608932 and rs2814707 using the Browse Raw Data feature.)There is increasing evidence that ALS belongs to a broader spectrum of neurodegenerative disorders, including Parkinson’s disease, so researchers speculate that genetic associations with ALS may also lead to clues about other disorders of the nervous system.(Note: A previous genetic association listed in 23andMe’s ALS Research Report, which provides information about lower-impact and preliminary research results, was not replicated in this study.)SNPwatch gives you the latest news about research linking various traits and conditions to individual genetic variations. These studies are exciting because they offer a glimpse into how genetics may affect our bodies and health; but in most cases, more work is needed before this research can provide information of value to individuals. For that reason it is important to remember that like all information we provide, the studies we describe in SNPwatch are for research and educational purposes only. SNPwatch is not intended to be a substitute for professional medical advice; you should always seek the advice of your physician or other appropriate healthcare professional with any questions you may have regarding diagnosis, cure, treatment or prevention of any disease or other medical condition.
SNPwatch: Genetic Variations May Increase Risk for ALS
September 10, 2009