The New Alzheimer's Gene and How it Affects Treatment and Prevention

Researchers have identified a new Alzheimer's gene variant that almost doubles the risk for late-onset Alzheimer's disease. These are the current findings and their future implications for the treatment and prevention of Alzheimer's disease.

New Alzheimer's Gene:

Researchers identified a variation in a gene they named MTHFD1L. People with the variation are nearly twice as likely to develop late-onset Alzheimer's disease, but the absolute risk for any single individual is still minor. The findings were presented at the annual meeting of the American Academy of Neurology. Late-onset Alzheimer's disease is the most common form of the disorder and affects people 60 and older. The World Health Organization estimates that there are currently 18 million people worldwide with Alzheimer's disease, and projects that will double to 34 million by 2025. Alzheimer's is a disease of the brain that causes impaired memory and dementia. There is no known cure, and current prevention and treatment approaches are very limited.

How the New Alzheimer's Gene Was Found:

The gene was identified through genome-wide association study (GWAS) which looks all across the entire genome for small variations in long stretches of DNA. It searches for variations that are more common in people with the disorder than in those without it. Investigators say they are excited about MTHFD1L in part because it links genetics and biology. The gene is involved in the metabolism of folate which influences body levels of homocysteine. High levels of homocysteine are also a risk factor for Alzheimer's. Also promising is the large number of study participants which helps build confidence in contrast to earlier research leads which couldn't be replicated. The initial study involved 2,100 people and was replicated with 2,500 more. Overall, genetic studies of Alzheimer's have made slow progress. A previous breakthrough came in 1993 with the discovery of the ApoE4 gene also associated with the increased risk for late-onset Alzheimer's disease.

Future Prevention and Treatment Implications of the New Alzheimer's Gene:

Prevention and treatment are complicated by the mix of genetic and environmental factors that cause late-onset Alzheimer's disease. WebMD estimates that 60% to 80% of the causes are genetic with 40% of that effect related to the ApoE4 gene. They calculate that the new Alzheimer's gene MTHFD1L may explain another 5% of this. All the research builds on itself and may help in developing drug treatment and prevention. If so, people who know they are at higher risk might be able to use drugs to prevent or slow the course of Alzheimer's disease.

Sources:

Charlene Laino, New Alzheimer's Gene Found, WebMD Health News

New Alzheimer's Gene Identified, Medline Plus, a service of the U.S. National Library of Medicine and the National Institutes of Health