Aug 14, 2017

Familial Alzheimer’s Disease: What You Need to Know About the Genetics of Dementia

Dementia is a complex condition that is yet to be fully understood. A vast amount of research goes into seeing what causes dementia symptoms and to see whether they can be stopped, reversed or prevented.  

There are many risk factors that can contribute to developing dementia – from lifestyle to genetics.

People affected by dementia are often concerned about whether the condition can be inherited. The genetics of dementia are complex and not yet fully understood.

Dementia can be so common, that though multiple members of the one family have the condition and there is still not a genetic link.

Though majority of dementia diagnoses are not inherited, there are some forms that are due to a genetic mutation that passes down the family line.

One such condition is Familial Alzheimer’s disease, which usually affect people under the 65 with symptoms appearing for some people in their 30s or 40s.

It’s believed that the mutated genes that causes this form of dementia play a role in the production and breakdown of amyloid – a protein that builds up in the brains of people with Alzheimer’s disease.

On average, half of the children of a person with familial Alzheimer’s disease will inherit the “faulty” gene. All those who inherit it will develop Alzheimer’s disease, and those who do not inherit the faulty gene will not subsequently pass it on to their children.

Genetic testing can identify the presence of gene mutations, as well as help determine if a person with dementia has familial Alzheimer’s, or if a child has inherited the changed gene from a parent and will develop the disease in the future.

However, genetic testing cannot determine when the symptoms will begin, though usually the age of onset is similar family members who have to condition.

When given the option to have genetic testing, some family members want to know for sure if they will later developing the condition, while others would rather not have the test as they feel they would be “burdened” in knowing their fate.

Untitled-1

Sporadic Alzheimer’s disease

There are two kinds of Alzheimer’s disease, Familial Alzheimer’s disease, which is extremely rare, and sporadic Alzheimer’s disease.

Sporadic Alzheimer’s disease can affect adults at any age, but usually occurs after age 65 and is the most common form of Alzheimer’s disease.

Many genetic and environmental factors combine to alter a person’s risk of developing Alzheimer’s disease.

According to Alzheimer’s Australia, having a close family member with the condition increases risk – but only by a small amount.

There are certain genes in dementia research known as “susceptibility genes” which partly explain this increased risk – predominantly the apolipoprotein E (ApoE) gene. Currently there are ten identified susceptibility genes that increase the risk of Alzheimer’s disease.

However, having one or two copies of the gene increases the chance of developing Alzheimer’s disease, but does not make it certain. Some people with apolipoprotein E gene never develop Alzheimer’s, and others who develop Alzheimer’s do not have the susceptibility gene.  

Having the ApoE4 gene has been associated with increased risk for cardiovascular disease, vascular dementia and Lewy body disease.

However, it should be noted that vascular dementia and Lewy body disease are very rarely inherited from family members.

What do you have to say? Comment, share and like below.

Disclaimer: Please be aware the above article is merely information – not advice. If users need medical advice, they should consult a doctor or other healthcare professional.

Leave a Reply

Your email address will not be published. Required fields are marked *

Advertisement
Advertisement
Advertisement

5 Reasons Why a Person with Dementia Might be Dehydrated

When a person has dementia, it is important to make sure they eat right and drink plenty of fluids. Dehydration is common in people with dementia, find out how you can best support them so that it doesn’t cause other health concerns. What is Dehydration? Dehydration is what happens when an individual loses more fluids... Read More

New standards don’t ensure quality care for people living with dementia

  The new aged care quality standards don’t ensure quality dementia care will be delivered to people living with dementia, says Dementia Australia. But the peak body for dementia in Australia has spoken to those with lived experience of dementia in forums all around the country to find out what is important to them.  Using... Read More

Diagnosed with dementia at 35: “It’s taken away the Megan we had”

Because dementia is commonly associated with old age, many don’t realise that the condition can be diagnosed in those as young as in their 30s. In Australia, there are currently around 400,000 people living with dementia. Of those, nearly 26,000 have what is known as ‘younger onset dementia’, the term given to dementia when it... Read More
Advertisement