In her dissertation, Annica Sjölander studied different variants of a gene called CDC2. DNA analyses of blood samples from both patients and healthy individuals showed that one gene variant was considerably more common among patients with Alzheimer’s disease. “This is the first discovery of a connection between this specific gene and Alzheimer’s. The findings must be confirmed in several other studies before we can be absolutely certain that it is a new Alzheimer’s gene that we have found,” explains Annica Sjölander. In the study this gene variant was found in roughly half of all patients with Alzheimer’s, compared with 35 percent of the healthy control group.
The dissertation shows that patients with Alzheimer’s disease who were carriers of the gene variant also had higher levels of the protein tau, which is associated with the disease. In patients with the disease the mean level of tau in the spinal marrow fluid is about three times higher than the level in healthy individuals of the same age.
The gene CDC2 is responsible for one of the phases when a cell divides and is only active when cell division is in progress. Other research has shown that CDC2 in Alzheimer’s patients is turned on inside nerve cells where cell division does not normally take place. “No one knows why the gene is activated, but it may be the result of a defect in the gene. It is also possible to speculate that the body is perhaps trying to compensate for lost nerve cells by having nerve cells divide,” says Annica Sjölander.
Title of dissertation: Alzheimer’s Disease: effect of tau-related genes on the pathology, neurochemistry and risk