Is Dementia Hereditary?

Dementia is a widespread and intricate condition that affects millions worldwide, encompassing over 150 distinct disease processes, including Alzheimer's, Lewy-Body, and Vascular dementia. Given the life-altering impact of dementia, many wonder about their risk factors. This article delves into the factors that influence the chances of developing dementia, with a focus on genetics.

Dementia Risk Factors

While a sedentary lifestyle, smoking, alcohol consumption, and factors like ethnicity and gender contribute to dementia risk, genetics is a key aspect to consider. However, it's essential to understand that dementia is not directly hereditary. Rather, certain genes can elevate your risk due to its complex nature. As the Alzheimer's Society stated in a 2021 article, dementia is a complex disease influenced by various factors.

APOE Gene and Alzheimer's Disease

The APOE gene is one genetic factor associated with an increased risk of dementia. According to Mayo Clinic, having one APOE gene can amplify your risk 2-3 times, while having two (one from each parent) can increase it by 8 times. It's crucial to note that possessing the APOE gene does not guarantee dementia but raises the risk. This gene is also linked to an increased risk of Lewy-Body and Vascular dementia and an earlier onset.

Frontotemporal Dementia

Frontotemporal Dementia demonstrates a strong genetic connection, with 30% of cases tied to family history. A specific gene mutation on chromosome 9, along with two other genetic markers, can influence the age of onset. If a parent carries the dominant mutated gene, their child faces a 50/50 chance of inheriting it. This gene mutation contributes to approximately 5-10% of all Frontotemporal Dementia cases.

Early-Onset Alzheimer's

Early-Onset Alzheimer's, characterized by symptoms appearing before the age of 65, has a substantial genetic link. Genes such as PSEN1, PSEN2, and APP mutations are associated with a high likelihood of developing symptoms. However, it's noteworthy that some individuals experience Early-Onset Alzheimer's without possessing any of these three mutated genes.

Genetic Testing

You can undergo genetic testing to assess your risk based on the gene mutations mentioned. It's essential to understand that genetic testing for the APOE gene does not definitively predict Alzheimer's. Doctors primarily use genetic testing for diagnosis and creating personalized treatment plans.