Is dementia hereditary?

A dementia diagnosis can be frightening, not only for the person affected but also for their loved ones.

It prompts more questions than can be answered straight away. One that is frequently asked is: ‘Is dementia hereditary?’

It is natural for those impacted to have concerns, worried that the risk is higher of their children or grandchildren being diagnosed in the same way later.

While there is still ongoing research into dementia and its causes, more recent studies suggest that 99 per cent of Alzheimer’s cases (the most prevalent type of dementia) are not hereditary.

Genetic links to dementia have only been seen in rarer forms of the disease, but they only account for a small proportion of overall cases.

However, as research into the different forms of dementia and its underlying causes continues, the answers we have now will change and evolve.

Dementia comes in many different forms, and each has its underlying causes, some of which include genetic factors.

Here, we’ll take a look at some of the most common types of dementia and discuss what is known at the moment about the role genetics have to play.

Alzheimer’s

It is estimated that around 850,000 people in the UK suffer from Alzheimer’s with the disease accounting for 60 to 80 per cent of all dementia cases.

However, in 99 per cent of cases, Alzheimer’s is not inherited and instead is often brought on by age.

People in their late 70s and 80s are in the most at-risk groups.

It is only those that have developed Alzheimer’s at an earlier age where there is an increased chance of it being passed to children or grandchildren.

Frontotemporal dementia

Around 16,000 people in the UK live with frontotemporal dementia, making it relatively rare when looking at dementia as a whole.

However, this also means that there is a higher probability that it will be passed on to children or grandchildren.

That being said, most cases are not genetically inherited; only 40 per cent of people who develop this type of dementia have a relative that has also been diagnosed.

Vascular dementia

In most instances, vascular dementia is not inherited and instead is brought about by underlying health conditions such as high blood pressure or diabetes.

However, it is important to acknowledge that these health conditions can also be passed genetically and socially through generations, increasing their risk of developing vascular dementia if not addressed.

Any genetic factors that increase the risk of vascular dementia are the same that put individuals at risk of a stroke, heart disease and other vascular issues.

Consequently, it is essential to maintain an active lifestyle to help reduce the risk of vascular issues and vascular dementia.

Rarer forms of dementia

There are some rarer conditions that can lead to dementia but, as the name suggests, they are relatively rare. Young onset dementia for example occurs in around three per cent of people before the age of 60.

In this instance, it is likely that the condition is hereditary and has been passed on due to a faulty gene.

In general, dementia that develops in early life is most often a result of a hereditary condition.

There is also a range of other rare types of dementia that is more likely to be passed down to children and grandchildren.

This includes diseases such as Huntington’s and Familial Prior.

It is thought that between one in 10,000 and one in 20,000 people in the UK are affected by Huntington’s and, because it is caused by a solo faulty dominant gene, there is a 50 per cent chance of it being passed on.

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Wednesday, 7 June 2023