It is normal for someone to feel down for a while, especially when people are going through a tough time and hectic life but the feeling of miserable most of the time, depression and cognitive impairment might be suggestive of Alzheimer’s disease.1 Without proper management, people with Alzheimer’s will lose their ability to perform basic activities of daily living.
There are two types of Alzheimer’s disease; late-onset and early-onset. Many studies have shown the role of Apolipoprotein E (APOE) genotype in the development of late-onset Alzheimer’s disease. APOE is a protein that functions in metabolizing fats and associated with Alzheimer’s disease and heart problems. There are three kinds of APOE; APOE ε2, APOE ε3 and APOE ε4. Early-onset Alzheimer’s disease primarily caused by mutations in the genes; amyloid precursor protein (APP), presenilin 1 (PSEN1) and presenilin 2 (PSEN2) usually happens in mid-30s to 60s.2,3
APOE ε2 is rare but it gives a protection against the Alzheimer’s disease which reduces the risk of developing Alzheimer’s disease later in life. APOE ε3 is more common and it has neutral characteristics that give neither decreasing nor increasing the risk of Alzheimer’s disease. While APOE ε4 is the one which increases of developing Alzheimer’s disease. People who carry APOE ε4 tend to have higher risk of developing Alzheimer’s disease compared to other genotypes, and it usually happens when they reach mid-60s or later when the symptoms will appear. From the genetic studies, those people with APOE ε4 are having a difficulty to eliminate amyloid-β from the brain causing its accumulation.2,4
When someone in your family members has been diagnosed with Alzheimer’s disease, it does not mean you will have it but indicates that you might be at risk. There is no specific treatment for Alzheimer’s disease, but with proper medical management, patients can prevent the complications and improve their quality of life.
- Bature, F., Guinn, B. A., Pang, D., & Pappas, Y. (2017). Signs and symptoms preceding the diagnosis of Alzheimer’s disease: a systematic scoping review of literature from 1937 to 2016. BMJ open, 7(8), e015746. https://doi.org/10.1136/bmjopen-2016-015746
- Liu, C. C., Liu, C. C., Kanekiyo, T., Xu, H., & Bu, G. (2013). Apolipoprotein E and Alzheimer disease: risk, mechanisms and therapy. Nature reviews. Neurology, 9(2), 106–118. https://doi.org/10.1038/nrneurol.2012.263
- Tanzi R. E. (2012). The genetics of Alzheimer disease. Cold Spring Harbor perspectives in medicine, 2(10), a006296. https://doi.org/10.1101/cshperspect.a006296
- Yamazaki, Y., Zhao, N., Caulfield, T. R., Liu, C. C., & Bu, G. (2019). Apolipoprotein E and Alzheimer disease: pathobiology and targeting strategies. Nature Reviews Neurology, 15(9), 501-518.