Influence of Genes on the Risk of Alzheimer's Disease

Curious about your genetic risk for Alzheimer's disease? Does someone in your family suffer from Alzheimer's disease? Although Alzheimer's is a complex condition influenced by age, family history, cardiovascular health, and lifestyle choices, genetics still play a crucial role as a risk factor.

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Genetic factors play a significant role in determining an individual's susceptibility to Alzheimer's disease. While other factors such as age, family history, cardiovascular health, and lifestyle choices like diet and exercise also play crucial roles, genetic variations in certain genes can impact key aspects of Alzheimer's pathology, including:

  • Formation of amyloid plaques
  • Abnormalities in tau proteins
  • Neuroinflammation
  • Neuronal death and synaptic dysfunction

Understanding these genetic influences can help in defining proactive measures such as maintaining a healthy lifestyle, managing cardiovascular risk factors, stimulating mental activity, maintaining social connections, and consulting healthcare providers for personalized guidance and support to reduce the potentially increased risk of Alzheimer's disease.

DNA Test Add-on
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Discover if you have an increased or decreased risk of Alzheimer’s disease, so you can take proactive steps to protect your brain health, delay or mitigate the onset of symptoms through lifestyle adjustments, and pursue early interventions.
Alzheimer's disease involves complex mechanisms that affect the function and structure of the brain. Genetic variations can influence factors such as the formation of amyloid plaques, abnormal tau proteins, and inflammation, all of which can contribute to the development of the disease.

Dementia

Alzheimer and dementia, what are the differences? In fact, Alzheimer’s is a type of dementia.
Dementia is a broad term used to describe a decline in cognitive function that is severe enough to interfere with daily life. It is not a specific disease but rather a group of symptoms associated with memory loss, thinking skills, and other mental abilities. Dementia is usually progressive, meaning it worsens over time.

Common Forms of Dementia
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There are several types of dementia, each with its own characteristics and underlying causes. Some of the most common types include:

  • Alzheimer's disease: this is the most common cause of dementia. It is characterized by the accumulation of beta-amyloid plaques and tau protein clusters in the brain, leading to the loss of nerve cells and brain tissue.
  • Vascular dementia: this type of dementia occurs when there is damage to the blood vessels in the brain, often due to strokes or other conditions that affect blood flow to the brain. Symptoms may include difficulties with reasoning, judgment, or memory problems.
  • Lewy body dementia: Lewy body dementia is characterized by the presence of abnormal protein deposits known as Lewy bodies in the brain. This condition is associated with a range of symptoms, including visual hallucinations, motor disturbances, fluctuations in alertness, and difficulties with cognitive processes such as thinking and reasoning.
  • Frontotemporal dementia: this type of dementia is caused by damage to the frontal and temporal lobes of the brain. It often affects behavior, personality, and language skills more than memory.
  • It is estimated that the remaining 27% have more than one type of dementia, known as mixed dementia, or a rarer form.

Influence of genetics on the risk of Alzheimer's disease

APOE gene
The apolipoprotein E (APOE) gene provides instructions for making a protein called apolipoprotein E. This protein helps the body process fats, such as cholesterol. The presence of the APOE gene, specifically the APOE-ε4 variant, is the most well-known genetic risk factor for late-onset Alzheimer's. Each person inherits a combination of three versions of the APOE gene:
  • ε2, the "protective" version
  • ε3, the "neutral" version and the most common
  • ε4, the "risk" version and the least common
Having one copy of the ε4 allele increases the risk of developing late-onset Alzheimer's by about three times; individuals who inherit two copies of the allele face an even greater risk, estimated to be eight to twelve times higher. However, having two ε4 alleles does not guarantee that you will develop Alzheimer's. On the other hand, having the ε2 version may lower your risk compared to the ε3 version. The ε3 version is believed to have a neutral effect on the risk of Alzheimer's.

In this DNA test, we identify which versions of the APOE gene individuals have. In addition to genetic mutations in the APOE gene, other genes that are, although to a lesser extent, associated with an increased or decreased risk of Alzheimer's disease are also analyzed.
CLU gene
The CLU gene provides instructions for making a protein called Clusterin, which is involved in many biological activities. Although the precise role of Clusterin is not entirely clear, it appears to contribute to cell survival and the body's ability to repair tissues.

In the context of Alzheimer's disease, research suggests that Clusterin may be involved in the development or progression of the disease. Individuals with certain CLU gene variants might have some protection against Alzheimer's. Some studies suggest that these genetic variants could lead to better protection of neurons against the harmful effects of amyloid-beta plaques and tau tangles, potentially reducing the risk of Alzheimer's disease.
PICALM gene
The PICALM gene provides instructions for making a protein called Phosphatidylinositol Binding Clathrin Assembly Protein, which is important for a process known as clathrin-mediated endocytosis. This process helps cells take up substances from their environment.

PICALM has become important in Alzheimer's research due to its link with the condition. Several studies have found that variations in the PICALM gene are among the strongest genetic risk factors for Alzheimer's disease.
CR1 gene
The CR1 gene provides instructions for producing a protein known as Complement Receptor 1, which plays a crucial role in regulating the immune system.

There is evidence that variations in the CR1 gene may contribute to an increased risk of developing late-onset Alzheimer's disease. Studies have linked certain versions of a specific genetic marker, rs6656401, to a higher likelihood of developing Alzheimer's. While the exact mechanisms remain unclear, scientists speculate that CR1 may influence the removal of beta-amyloid, a protein that forms the characteristic plaques in the brains of Alzheimer's patients. Variations in the CR1 gene might affect how efficiently this protein clears beta-amyloid, potentially leading to greater plaque accumulation and subsequent brain damage.

This DNA test is not available yet. Please contact us for more information.




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