New genetic form of Alzheimer’s identified

After all, a gene that increases the risk of Alzheimer’s may also be the origin of the disease. The importance of APOE4.

Anyone who has Alzheimer’s, or is close to someone who has Alzheimer’s, will have heard of APOE4.

Decades ago, APOE4 was identified as a gene that can increase the risk of Alzheimer’s – among other risk factors.

But now a study puts this gene on another level: it is not just a risk factor; is also the origin in some cases.

The analysis carried out by Spanish scientists, which evaluated more than 3 thousand brains, suggests that people with two copies of APOE4 are patients of a different type of Alzheimer’s, of genetic origin.

Scientists have no doubt: they have identified a new genetic form of Alzheimer’s.

The gene also becomes a cause of the disease, in specific cases (two copies of the gene).

In the study, virtually all people with the double variant had Alzheimer’s.

What’s more: these patients are likely to develop Alzheimer’s earlier than the average. In other words, the gene anticipates the onset of the disease.

Juan Fortea, lead author of the study, said these findings mark a distinction with “profound implications”.

“We propose a new concept of Alzheimer’s. Until now, APOE variants were considered risk factors. But our suggestion is that the case of homozygotes be included in the growing family of genetically determined Alzheimer’s disease.”

It is estimated that 15% of Alzheimer’s patients are carriers of two copies of APOE4, which means that these cases “can be traced to a cause and the cause is in the genes”, added Fortea, quoted in the Associated Press.

Until now, it was thought that genetic forms of Alzheimer’s represented less than 1% of all cases. According to Juan Fortea, between 2% and 3% of the world’s population has two copies of APOE4 in their DNA.

Important point: the team of scientists argues that a gene duplication test if a middle-aged person begins to show symptoms of dementia.

And the expert reinforces the thesis: Alzheimer’s is not just a disease. There are versions.