Alzheimer’s Genetic Variant Improves Brain Function

Alzheimer’s, the most common form of dementia, is a disorder in the brain that can be fatal and still has no known cure but has treatment for its symptoms. It is associated with the loss of memory and slowed thinking. While this is common in older people, experts now claim there are about 500,000 people at the age of 30, 40 or 50 already suffering from this disease or any related dementia.

Recently, a study showed that a genetic variant that elevates the risk of this disease can actually improve the function of the brain, particularly for those carriers who are younger.

Professor Duke Han from the Chicago Rush University Medical Center said that based on an evolutionary standpoint, the results seemed to make sense.

His research focused on epsilon 4, a variant of a gene called apolipoprotein E or APOE, which is considered as the best established genetic variant for this brain disorder. Having one copy of the variant raises the risk of the disease at least four times compared to patients who have other types of the gene.

The positive feedback on epsilon 4 actually started years ago when Professor Han’s research team examined the APOE genes of 78 US troops, all of whom suffered brain injuries during their time in Iraq. Sixteen of the soldiers had at least a copy of epsilon 4. They were expected to have gotten worse over time, but the result was the opposite: those with epsilon 4 improved their attention spans and memory.

Another study conducted earlier found that young women with epsilon 4 have higher IQs than those without it. The women scored seven points higher on a common intelligence exam under the non-verbal portion.