Alzheimer’s Disease and COVID-19 in a Reference Panel

With developing research happening regarding COVID-19, researchers have found a connection between those with two copies of the ApoE4 gene and more severe cases of COVID-19. Based on a study in the UK, they found that 410 out of the 100,000 people with two copies of the ApoE4 gene would test positive for the virus (Saey). This number was higher compared to those with only one version of the gene or two copies of ApoE3. The ApoE gene is one of the most common risk factors for those with dementia or Alzheimer’s Disease. While this does not mean that those with two copies of the ApoE4 gene are guaranteed to get AD, they are just at a greater risk among those without two copies. Although it is uncertain why those with two copies are more likely to develop the disease, researchers hypothesize that it could be “a gain of toxic function, a loss of neuroprotective function, or both” (Kim, et. al, p. 287). Those who are carriers of the ApoE4 gene are at a higher risk for presenting with a neuroinflammatory response in the presence of viruses because of the neuroinflammation role of ApoE (Kim, et. al, p. 295). Because COVID is a strong virus, it can lead to long term neurodegeneration and even death.

In Neuner et. al’s article, “Harnessing Genetic Complexity to Enhance Translatability of Alzheimer’s Disease Mouse Models: A Path toward Precision Medicine,” they discuss the importance of genetic factors underlying Alzheimer’s Disease. In previous studies, researchers have failed to include genetic diversity into their experiment; however, this is essential in understanding what really leads to AD. To do this, they created a reference panel called AD-BXD which included two essential parts as they describe to be “the 5XFAD transgenic line on an otherwise fully inbred . . . that recapitulates various aspects of the human disease” and “the BXD genetic reference panel” which includes many genes that are known risk factors for AD (Neuner, et. al., p. 401). By using these panels in mice, this will allow them to reproduce the same mouse over and over again and study the particular traits of that mouse. They will then be able to compare these panels to the human panel and see what genes underlie AD in individuals. With this, they will be able to identify “genetic modifiers of AD susceptibility that can be targeted as new therapeutic opportunities” (Neuner et. al, p. 408). This reference panel will be extremely beneficial in the clinical field and gives those with AD some hope that there could be ways to slow down, help with, or prevent the disease.

Both of these studies looked at the importance of genetics in Alzheimer’s Disease, and more specifically, the ApoE gene. Experiments such as those used in the reference panel can be helpful in further looking at cases such as how those with two copies of the ApoE4 gene are more severely affected by COVID-19 and what causes this severity. Once they identify these causes, it may be possible to prevent the severe side effects of the virus.


Citations

Kim, Jungsu, et al. The Role of Apolipoprotein e in Alzheimer's Disease. 13 Aug. 2009, www.ncbi.nlm.nih.gov/pmc/articles/PMC3044446/.

Neuner, Sarah M., et al. “Harnessing Genetic Complexity to Enhance Translatability of Alzheimer’s Disease Mouse Models: A Path toward Precision Medicine.” NeuroResource, 6 Feb. 2019, doi.org/10.1016/j.neuron.2018.11.040.

Saey, Tina Hesman. “Genetic Risk Factors for Alzheimer's Also Raise the Risk of Getting COVID-19.” Science News, 29 May 2020, www.sciencenews.org/article/coronavirus- covid-19-genetic-risk-factors-alzheimers-disease.