Miller School Genetic Researchers Identify New Gene Associated with Increased Risk of Alzheimer's Disease
A gene that appears to increase a person's risk of developing late-onset Alzheimer's disease, the most common type of the disease, has been identified by a team of researchers led by Margaret Pericak-Vance, Ph.D., director of the John P. Hussman Institute for Human Genomics at the University of Miami Miller School of Medicine.
The research was presented as part of the late-breaking science program at the American Academy of Neurology's 62nd Annual Meeting in Toronto this week. The gene, abbreviated MTHFD1L, is located on chromosome six.
"Only recently have common variants in genes other than APOE been convincingly shown to be associated with a person's risk of developing late-onset Alzheimer's disease," said Dr. Pericak-Vance, senior author and principal investigator of the study.
Researchers looked at gene variation throughout the human genomes of 2,269 people with late-onset Alzheimer's disease and 3,107 people without the disease through what's known as a genome-wide association study. Such studies involve looking at long stretches of DNA to identify small differences in the genetic sequence between people with and without Alzheimer's disease.
The study found that individuals with a particular variation in the gene MTHFD1L may be almost twice as likely to develop Alzheimer's disease as those people without the variation. "We are hopeful our identification of MTHFD1L as a risk gene for Alzheimer's disease will help us to better understand how this disease develops and potentially serve as a marker for people who may be at increased risk," said Adam Naj, Ph.D., the first author of the abstract reporting the discovery and post-doctoral fellow at the Hussman Institute for Human Genomics.
"Identifying this gene is important because the gene is known to be involved in influencing the body's levels of homocysteine, and high levels of homocysteine are a strong risk factor for late-onset Alzheimer's disease," said Dr. Pericak-Vance. "In addition, variations of the MTHFD1L gene have been reported to possibly increase the risk of coronary artery disease. Since the function of blood vessels in the brain may affect Alzheimer's disease, this finding may also help us understand how homocysteine levels and blood vessel function in the brain affect Alzheimer's disease."
The World Health Organization estimates that there are currently 18 million people worldwide with Alzheimer's disease, and this figure is projected to nearly double to 34 million by 2025. At least five million Americans are living with the disease today.
The study was supported by the National Institute of Aging, part of the National Institutes of Health. The research team responsible for the work includes collaborators Jonathan Haines, Ph.D., from Vanderbilt University Medical Center and Joseph D. Buxbaum, Ph.D., from Mount Sinai School of Medicine.