ST. LOUIS, MISSOURI — Scientists at a U.S. university have identified genes linked to Alzheimer’s Disease. The discovery could help researchers develop new drugs against the debilitating brain malady.
As life expectancy increases around the world, more and more people survive into their 70s, 80s, and beyond, when the memory loss, personality changes, and other signs of Alzheimer’s develop.
The “gold standard” for Alzheimer’s diagnosis has long been something visible only in an autopsy - characteristic deposits in the brain known as plaques and tangles.
The plaques are clumps of a protein called beta amyloid. The tangles are associated with another protein, called tau, which was the subject of this research.
“We took 1,200 people and measured their spinal fluid levels of tau, and we wanted to understand what genes regulated levels of tau in those people,” said researcher Alison Goate, who studies genetic approaches to neurological diseases at Washington University School of Medicine in Saint Louis.
She and her colleagues were specifically looking at genes linked to the tau protein. “And the reason for doing that is because previous studies have shown that higher levels of tau in the spinal fluid are associated with developing disease,” she said.
Her team analyzed DNA molecules and identified four regions of genetic material associated with tau levels as measured in the spinal fluid, and then looked for links between those four regions and Alzheimer’s Disease. And they found some correlation in three of the four, “which make us feel more confident that, at least in the case of those three genes, they are not only influencing levels of tau in the spinal fluid, but having some impact on risk for Alzheimer’s Disease.”
Researchers now believe that Alzheimer’s begins killing off brain cells years before any obvious symptoms develop. So you might wonder if this work will lead to a genetic test for Alzheimer’s.
Probably not, Goate said.
But knowing which genes are linked to higher tau levels might help drug researchers, who so far haven’t had much success with medicines that target beta amyloid, the other protein linked to Alzheimer’s.
“And that maybe they will turn out to be useful drug targets for modifying tau levels in the way that we modify cholesterol levels to reduce heart disease,” she said.