Researchers have long been aware that Alzheimer’s disease is more likely to occur in people with specific genetic risk factors. Now, it appears that it may also be genetically linked to high levels of lipids (fats) in the blood, which is, in turn, associated with the development of cardiovascular disease. Gaining insight into this relationship could provide researchers with a new avenue for the development of treatments for both Alzheimer’s disease and cardiovascular conditions.
Alzheimer’s Disease and Genetics: A Refresher
We have already covered the genetic basis of Alzheimer’s disease, so there is no need to get too in depth here. The most common form of Alzheimer’s (the type that occurs in old age) is not a hereditary condition, which means that it is not passed directly from parent to child via genetic materials. However, there is evidence that the presence of a certain gene (known as APOE) significantly increases the chances of developing Alzheimer’s disease. Early-onset Alzheimer’s disease, on the other hand, is highly hereditary in nature, but it is not our focus here.
The Cardiovascular Connection
Researchers were motivated to search for a potential genetic link between Alzheimer’s disease and cardiovascular disease because there is a history of evidence that hints at an existing relationship between the two. For example, vascular diseases (including cardiovascular disease) are associated with cognitive impairments and are often found in the postmortem examinations of Alzheimer’s-affected brains. Such findings raised hopes that Alzheimer’s disease could be prevented or controlled by treating cardiovascular symptoms. Unfortunately, this approach has yet to deliver successful results.
A Newly Discovered Genetic Link
A recently published study in the journal Acta Neuropathologica outlines the newly discovered genetic relationship between Alzheimer’s disease and cardiovascular conditions. Specifically, six different genomic areas (locations in our DNA) were identified as being associated with both the development of Alzheimer’s disease and high blood lipids like cholesterol.
When certain variations are present in these areas then the likelihood of having cardiovascular disease (due to increased levels of fat in the blood) and Alzheimer’s disease are significantly increased. A genetic variation describes a difference in the arrangement of molecules within sections of DNA when comparing them between individuals. Everyone has genetic variations of some sort, as they are a natural result of reproduction.
The discovery of new genetic links to both Alzheimer’s and cardiovascular diseases presents multiple opportunities for the treatment and, ideally, prevention of both conditions. Primarily, the results indicate that these conditions could be caused or exacerbated by a genetically-based impairment in the body’s ability to process lipids. Researchers are now looking into the possibility of treating or preventing Alzheimer’s disease by addressing these specific impairments, rather than focusing on cardiovascular disease as a whole.
Among the most promising secondary findings from this study is the identification of several genes that are associated with Alzheimer’s disease. Previously, only a single genetic link to the condition was widely recognized. Furthermore, it was confirmed that the children of people with Alzheimer’s disease are more likely to carry these variants, thus providing a new avenue for assessing genetic risk.