Is Alzheimer's Disease Hereditary?

Alzheimer's disease, often referred to as senile dementia, typically affects individuals aged 65 and older. However, the question of whether it is hereditary is complex and depends on the specific type of dementia involved.

Types of Dementia and Their Hereditary Risk

Reversible or treatable forms of dementia—such as those caused by vitamin B12 deficiency, hypothyroidism, or anemia—do not have a hereditary component. In these cases, cognitive impairments can often be improved or fully resolved with appropriate medical treatment. Therefore, these conditions are not considered genetically transmissible.

Alzheimer's Disease and Genetic Factors

Alzheimer's disease, the most common form of irreversible dementia, does have a genetic component. It can be broadly categorized into two types based on age of onset: late-onset Alzheimer's (occurring at age 65 or older) and early-onset Alzheimer's (appearing before age 65).

Early-Onset Alzheimer's and Heredity

Early-onset Alzheimer's, sometimes referred to as presenile dementia, has a stronger genetic link. This form is associated with specific gene mutations such as those in the APP, PSEN1, and PSEN2 genes. These mutations can be passed down through families, significantly increasing the risk of developing the disease.

Predictive Patterns in Family History

If a close family member develops Alzheimer's before the age of 65, there is a higher likelihood that subsequent generations may also be affected—even at an earlier age, such as in their 40s or 50s. This pattern suggests a strong hereditary influence, particularly in families with a known genetic mutation linked to the disease.