How fast will your brain age? Scientists identify key gene

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YOUR brain may start aging at a dramatically faster rate when you hit age 65 — or it may not, depending on which version of a particular gene you have, a new study suggests. In the study, scientists identified a gene that appears to control the speed at which the brain ages, and they say that a particular version of it may offer protection against a host of age-related neurological diseases, including dementia.
The gene, called TMEM106B, kicks into action at about age 65. Soon after that, people with bad copies of this gene will have a brain that looks 10 to 12 years older than people of the same age who have working copies, the scientists said.
The discovery may allow doctors to identify which people are at an in-creased risk for neurological diseases by virtue of having a faulty TMEM106B gene. It also may help develop drugs that target this gene to promote healthier brain aging, the researchers said. The study de-scribing this work appears today (March 15) in the journal Cell Systems. In recent years, scientists have identified numerous genes associated with Alzheimer’s disease, Parkinson’s disease and other neurological conditions.
“But those genes explain only a small part of these diseases,” said study co-leader Herve Rhinn, an assistant professor of pathology and cell biology in the Taub Institute for Alzheimer’s Disease and the Aging Brain at Columbia University Medical Center in New York. “By far, the major risk factor for neurodegenerative disease is aging. Something changes in the brain as you age that makes you more susceptible to brain disease.” The genetic-based instructions ex-pressed by TMEM106B may be that “something,” Rhinn said. The instructions may either protect against or accelerate the ravages of aging. [6 Big Mysteries of Alzheimer’s Disease]
“If you look at a group of seniors, some will look older than their peers, and some will look younger,” said Dr. Asa Abeliovich, a professor of pathology and neurology at the Taub Institute and a co-author of the study. “The same differences in aging can be seen in the frontal cortex, the brain region responsible for higher mental processes.” Previous studies have associated TMEM106B with a rare form of dementia called frontotemporal lobar degeneration. However, the new study shows that the TMEM106B gene is more broadly associated with brain age, and underlies how well seniors maintain their cognitive abilities, according to Rhinn and Abeliovich.