Predicting Who Gets Alzheimer's

Young brains hold clues to the risk of developing Alzheimer's disease decades before any symptoms arise. This lends support to the idea that the brain's memory function may gradually wear itself out in those who go on to develop the disease later in life. According to a new neuroimaging study by scientists from the University of Oxford and Imperial College London, those who inherit one copy of a specific genetic variant known as "APOE4" have up to four times the normal risk of developing the late-onset variety of the disease and people who have two copies have around ten times the normal risk.

Differences in the region of the brain involved in memory, known as the hippocampus, have previously been shown in middle-aged and elderly healthy carriers of APOE4. However, this latest study is the first to show hyperactivity in the hippocampus of healthy young carriers. It is also the first to show that APOE4 carriers' brains behave differently even at 'rest'. Even when the APOE4 carriers were not performing a memory-related task, the researchers could see that carriers and non-carriers each had distinct patterns of brain activity.

These latest findings could lead to strategies and treatments for preventing this condition. About a quarter of the population carries at least one copy of the gene variant and certainly not all who do will go on to develop Alzheimer's.