Which APOE Gene Causes Alzheimer’s Disease?

Unfortunately, there has not been any specific gene identified that shows to directly cause Alzheimer’s disease. However, studies have shown that your risk of developing diseases like dementia and Alzheimer’s may increase if you have at least one copy of the APOE4 gene.

Alzheimer’s disease has two types that are based on the age at which it starts: Late-onset and early-onset. Those who develop Alzheimer’s after the age of 65 are considered late-onset, while those who develop it before age 65 are early-onset. The disease slowly causes memory loss (dementia).

Though the APOE4 gene might increase the risk of developing Alzheimer’s, those who have at least one of the APOE2 genes may be protected from the disease. If the disease does occur in a person with this type, it often occurs later in life than those with the APOE4 gene.

Risk Factors for Alzheimer’s Disease

Age is one of the most common risk factors for Alzheimer’s and other types of dementia, even though these diseases are not a normal and natural part of aging. Their risk is typically a combination of factors. Family history is also included in these risk factors. Research suggests that those who have direct family members with Alzheimer’s are more likely to develop the disease. Your lifetime risk can increase if you have more than one family member with the condition. Lifestyle and environmental factors, like poor sleep, smoking, cardiovascular disease, or diabetes, can also increase your risk.

Test results of genetic counseling show that genes are involved in increasing the risk of Alzheimer’s disease. There are two categories of genes that influence whether you might develop this disease. These are:

• Risk Genes: These are the types we mentioned earlier – the APOE genes that can increase your risk of developing a disease but do not guarantee that you’ll get it.
• Deterministic Genes: These are the genes that ensure and directly cause you to develop a condition. According to scientists, less than 1% of cases of Alzheimer’s are caused by these deterministic genes.

What is APOE Genetic Testing?

APOE genetic testing helps to identify which type of apolipoprotein E (APOE) genotype you have. By identifying this, you’ll better understand what type of risk you might have for developing Alzheimer’s disease since having a specific genotype (like APOE4) can increase your risk.

A higher risk of developing a condition does not mean you’ll develop it. This information only tells you whether or not you might be more likely to. There are many things that go into your risk of developing certain conditions – genetics being one of them. So, just because you might have the gene that is connected to an increased risk of Alzheimer’s does not mean you’ll end up developing it. It’s important to discuss test results with a genetic counselor.

The Link Between APOE Gene and Diseases

Understanding your health can start with discovering how your APOE gene is linked to various diseases. Specifically, as we mentioned, this gene shows whether you have a higher chance of getting diseases like Alzheimer’s and even heart disease. Depending on the type of APOE gene, you might have a higher chance of getting specific diseases.

That’s what makes this genetic testing so valuable. It can help you understand the link between your genetics and disease risk so that you can work on ways to prevent or manage these conditions.

The Connection Between APOE and Alzheimer’s Disease

Scientists have focused a lot of research on the APOE gene and how it is linked to Alzheimer’s disease. This condition is serious as people slowly lose their memory and sense of self. In researching the APOE gene, they’ve found that the APOE4 version can put someone at a higher likelihood of getting Alzheimer’s after the age of 65. Having one copy of this specific gene seems to double or triple a person’s genetic risk for Alzheimer’s.

However, just because the risk might be there does not mean a person will develop it. In fact, lifestyle factors, family history, and other factors like ethnicity can contribute to a higher risk of causing this disease than having this specific APOE gene.

There are also ways to decrease your risk. Research has shown that those who engage in even just 30 minutes of regular exercise might be up to 20% less likely to develop dementia and Alzheimer’s disease than those who don’t exercise.

Who Should Get Tested for APOE Genetic Variants?

Testing for the APOE genetic variants isn’t always recommended because there can be many causes for the development of diseases, and it is unlikely to be caused by a single gene. In other words, the results of this genetic test can’t fully predict whether a person will develop Alzheimer’s disease.

However, testing for early onset of the disease might be helpful if you have a family history of Alzheimer’s disease. If you’re someone who has a direct relative, like a parent or sibling, who has been diagnosed with early-onset Alzheimer’s, you might want to consider genetic testing, especially if that relative is no longer around to be able to test. Having those results can help you make decisions and plan better. They may also open up opportunities for you to participate in clinical trials for advanced preventative therapies.

Benefits of Knowing Your APOE Status

If you have a direct relative with Alzheimer’s disease, you might benefit from knowing your APOE status. Here are some of the benefits that could help you figure out whether or not to test:

Early Intervention

Knowing early on whether or not you could be at a higher risk for Alzheimer’s or heart disease can help you start taking steps to avoid increasing your risk further. This might mean making lifestyle changes such as eating better, getting more physical activity, lowering stress, and stopping or reducing smoking or drinking.

Personalized Treatment

When you know your APOE status, you can begin getting personalized treatment. For example, if there’s a chance you could have a higher risk for heart problems in the future, your doctor might work with you to focus on managing things like your cholesterol and blood pressure.

Healthcare Planning

Being able to understand your APOE status can make your healthcare planning easier. Once you know, you can talk with your doctor or a genetic counselor about your possible risks for illnesses, what signs you should be on the lookout for, and what choices you can start making to stay healthy.

Conclusion

The APOE gene test is intended to provide you with information regarding your risk for certain conditions like Alzheimer’s disease and heart disease. Though your APOE status might not be specifically related to whether or not you develop these diseases, it can give you information about whether you could be at a higher risk – especially if you have a strong family history of these conditions.