Is Dementia Hereditary?0 USER TIPS ADD YOUR TIP
In most cases, dementia isn’t linked to your genes. The majority of people with dementia do not have a family history of it. Even in families with a strong history of dementia, doctors can’t always pinpoint why some family members develop dementia and others don’t. Still, there are some cases of dementia that do have a genetic underpinning. Here’s a breakdown of what’s known about the genetics of the most common forms of dementia:
Alzheimer’s is the most common form of dementia, and also the most well-known. It causes brain cells to be damaged and ultimately destroyed, leading to memory loss and reduced mental capacity.
Is it hereditary? Sometimes. In a small number of cases, scientists have been able to isolate specific genetic mutations that put people at greater risk for developing the condition (especially at younger ages).
Lewy body dementia
Lewy Body Dementia (LBD) is the second most common form of dementia and is associated with abnormal protein deposits—Lewy bodies—that develop in different regions of the brain. LBD can trigger hallucinations, as well as motor symptoms that are similar to Parkinson’s disease (namely, tremors, balance and walking issues, and stiffness).
Is it hereditary? Unclear. If you have a family member who has suffered from LBD, you may be at increased risk, but the cause of LBD is still unknown. While some genetic variants have been associated with the onset of the condition, most cases of the condition aren’t thought to be hereditary.
When blood flow to the brain is blocked—such as during a stroke—brain cells can die, leading to impaired function. But a stroke isn’t the only cause of vascular dementia. Heart disease can also limit blood flow to the brain over time, slowly killing off brain cells and causing cognitive issues. Memory may not be the first symptom of vascular dementia, as cognitive decline depends on which area of the brain is experiencing cell death.
Is it hereditary? Only in very rare cases. The vast majority of vascular dementia can be attributed to environmental and lifestyle factors that can cause a stroke and other chronic diseases that impair vascular function.
Nerve cells in the frontal and temporal lobes of the brain are responsible, in part, for behavior and language. When these nerve cells degenerate, it’s called frontotemporal dementia. Significant personality changes are a common symptom of this type of dementia, which typically occurs in people under the age of 65.
Is it hereditary? In some, but not all, cases. Studies show that 10 to 15 percent of people diagnosed with frontotemporal dementia have a strong family history of that type of dementia and/or amyotrophic lateral sclerosis (ALS), with a possible gene mutation. Another 20 to 25 percent have some family history of neurodegenerative disease, such as Alzheimer’s or Parkinson’s disease, which may or may not have a genetic link.
Huntington’s or Parkinson’s disease–related dementia
Both of these conditions are progressive neurological disorders that can also trigger dementia as the disease worsens.
Is it hereditary? For Huntington’s disease, there’s no mystery: The debilitating disease is caused by a mutation in the HTT gene. In the case of Parkinson’s, only about 15 percent of people who develop it have a family history of the condition, which is why scientists believe environmental factors may play a larger role.