Information About Genetic Testing
Having a test to look for a faulty gene that causes dementia is only appropriate for a very small number of people. This is because inherited dementia is rare.
If you are worried that you have a strong history family of young onset Alzheimers disease or frontotemporal dementia, you can speak to your doctor about this.
Not all gene mutations that cause dementia have been identified, meaning that some families may have many affected members, but no mutation can be found. Therefore, a negative test result cannot always rule out a genetic cause of a disease.
If a test is appropriate, your doctor should be able to refer you to a genetic counsellor or specialist. This could be a cognitive neurologist or memory clinic psychiatrist. They will discuss with you the pros and cons of taking a test and what will be involved. They will also tell you where the results will be kept, who they will be shared with, and what the next steps would be. For people found to have a genetic mutation that causes dementia, these discussions will also cover the options available if you are considering starting a family.
To find out more about genetic testing and what support is available you can visit www.raredementiasupport.org or call 020 3325 0828. Leave a message and you will be referred to the most appropriate team member.
Genes And Late Onset Alzheimers Disease
Late onset Alzheimers disease affects people over the age of 65. It is the most common type of Alzheimers and is likely to be caused by a combination of risk factors including our age, lifetsyle and environment. Our genetics also play a part.
To date, scientists have found versions of over twenty different genes that are associated with an altered risk of developing Alzheimers disease. However, having one of these versions may only have a small effect on our total risk. There is still a lot to be understood about these genes and their role in the development of late onset Alzheimers.
The most well known gene with the largest effect on our risk is called APOE. This gene makes a protein that helps keep our brain cells healthy. There are three different versions of it APOE2, APOE3 and APOE4 and we inherit one version of the APOE gene from each parent.
People who inherit one copy of APOE4 are around three times more likely to develop Alzheimers disease. About one in fifty people inherit two copies of APOE4 one from each parent. They may be more than eight times more likely to develop Alzheimers. However, due to other contributing factors, such as age and lifestyle, people who inherit APOE4 still may never develop the disease.
More information about young onset Alzheimers disease can be found here.
Is genetic testing available for young onset Alzheimers?
You can read a personal account about deciding to be tested for a gene mutation on our blog here.
Can Frontotemporal Dementia Be Inherited
Sometimes, yes. FTD is relatively rare compared with Alzheimers disease or vascular dementia, but it can be passed on directly from parent to child. A diagnosis of FTD can therefore cause a great deal of worry to someone who has children or grandchildren.
Most FTD is not directly inherited, but about 40 per cent of people who develop the condition will have at least one close relative diagnosed with some kind of dementia. This can include FTD, Alzheimers disease or amyotrophic lateral sclerosis . In general, the greater the number of relatives who have had dementia particularly FTD or ALS the greater the chances of developing familial FTD.
Of the different types of FTD, the behavioural form is the one that is inherited most often. The type of FTD which starts as primary progressive aphasia is only rarely inherited.
There are lots of different genes causing familial FTD, each with its own pattern of inheritance. If you are concerned about either passing on an FTD gene or inheriting the disease from your parents, you can ask your GP to refer you to a genetic testing service in your area. These people are specially trained to guide you through the process of finding out whether you have a gene that causes FTD. You can also get in touch with a specialist support group at Rare Dementia Support, who can provide information and advice about how to cope with having a heritable form of FTD in your family.
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Who Is At Most Risk
Genetics plays a role, so a person with the 4 variant in the APOE gene has a higher likelihood of developing late-onset Alzheimers, but other non-genetic factors are also associated with higher or lower risk. And many of these factors are interrelated diet, exercise, and heart health, for instance.
Finding Out Your Genetic Or Hereditary Risk May Not Ultimately Affect You
Because risk factors like blood pressure and diet are more influential than genetics , you might ultimately decide that you dont really need to know your genetic or hereditary risk. Anyone, whether they have a family member with Alzheimers disease or not, can benefit from working to lower their risk.
A lot of my patients decide against . Because what are you going to do? Youre going to do diet and exercise, Lyden said. So if youre going to do diet and exercise anyway, why bother finding out that you have this gene.
If you just found out a relative has been diagnosed with Alzheimers disease, try not to jump to the conclusion that you will 100% get it, too. Science does not indicate you need to assume your diagnosis is coming. For the best chance of lowering your risk of Alzheimers, focus on maintaining a healthy lifestyle. And if you have a loved one with Alzheimers and are looking for support, check out these articles written by people who have been there:
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Genes And Frontotemporal Dementia
Frontotemporal dementia , originally called Picks disease, is a rarer type of dementia mostly affecting people under the age of 65 years. The symptoms of FTD can be quite varied but include changes that mostly affect behaviour or language. There are different types of FTD, and these are likely to have different causes.
Some people with FTD have a family history of dementia and the condition may be inherited in some of these families. For behavioural variant FTD, a third to half of people could have a family history. This figure is thought to be much lower for other types of FTD.
Overall, around one in ten cases of FTD are thought to be caused by a faulty gene passed down in families. Several genes have been found that can cause these inherited types of FTD, including:
Mutations in the MAPT gene can cause the tau protein to behave abnormally, forming toxic clumps that can damage brain cells. We still need to understand more about how mutations in progranulin and C9ORF72 cause the disease.
The C9ORF72 gene can cause people to develop motor neurone disease, FTD or both conditions, and may affect members of the same family differently.
In cases of FTD that are not caused by faulty genes, the risk factors are not yet fully understood, and research is ongoing.
Is genetic testing available for frontotemporal dementia?
There Is A Genetic Test For An Alzheimers Gene But It Doesnt Predict If Youll Get The Disease
Scientists identified one gene, called APOE, that has been shown to potentially affect your risk of developing Alzheimers disease. Genetic testing, for example through the at-home testing company 23andMe, offers a test that will discover if you have the version of the gene, called APOE-e4, that is associated with an 15- to 20-percent increase in the likelihood of developing Alzheimers. Every person has zero, one or two copies of APOE-e4, and the more you have, the greater your risk.
However, its important to remember that even if you do have the bad gene, that doesnt necessarily mean you will get Alzheimers disease. Not everyone with the risky gene gets Alzheimers, and not everyone who has Alzheimers has the risky gene, so its not a predictive test.
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How Can I Reduce My Risk Of Dementia
For the vast majority of people, our genes are only one factor affecting our risk of dementia. There are many other factors involved, such as age and lifestyle. While we cannot change our age or genes, research has found that up to a third of all cases of dementia could be avoided through lifestyle changes.
There are simple things we can do that may help lower our risk:
You can find more detailed information about how you can reduce your risk of dementia here.
Can Vascular Dementia Be Inherited
In most cases, vascular dementia itself is not inherited. However, the underlying health issues that sometimes contribute to this condition, such as high blood pressure or diabetes, may be passed on from one generation to another.
Other than in a few, very rare cases, parents cannot pass on vascular dementia to their children. However, a parent may pass certain genes that increase the risk of developing vascular dementia.
The sort of genes that increase the risk of vascular dementia are often the same ones that increase the risk of high blood pressure, diabetes, heart disease and stroke.
For this reason, having a healthy lifestyle, such as eating well and staying physically active, are probably more important for preventing vascular dementia than they are in Alzheimer’s disease.
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Genes Which May Influence Alzheimers Disease
Having a close relative with the Alzheimers disease is not evidence of a genetic link. People who are influenced by risk factor genes are only at a slightly increased risk in developing the disease than the average population.
The most important gene discovered to date is the Apolipoprotein E gene, which is found in chromosome 19. This gene occurs in three forms in humans: types 2, 3 and 4. Every person in the world carries two Apolipoprotein genes: they can be the same type , or a mixture of two types . What has been found is that people with at least one type 4 and especially those with two, such as 4,4, are at an increased risk of developing Alzheimers disease earlier in life than those with the other types of Apolipoprotein E. Nevertheless half of the people aged 85 who have 2 copies of apolipoprotein E 4 do not have symptoms of Alzheimers disease at that age.
People with type 2, especially 2,2, appear to be protected against developing Alzheimers disease, until much later in life. Researchers do not understand why this is so, and there is much research underway to find out why.
The type of Apolipoprotein does not mean definitely that Alzheimers disease will or will not occur. Indeed it is known that some people can reach 90 with type 4 and not develop dementia, whereas others with type 2 can develop dementia much earlier in life. What this means is that the type of Apolipoprotein a person has, is not enough on its own to cause Alzheimers disease.
Scientists Cant Say For Sure Whether Family History Predicts Alzheimers Or Not
There is one rare type of Alzheimers disease, called early-onset familial Alzheimers disease , that is known to be genetic and will appear throughout a family tree. However, this accounts for only 5 percent of all Alzheimers cases.
For the rest, Alzheimers research is not conclusive. Some studies indicate that people with a parent or sibling who has Alzheimers have a slightly higher risk of developing it themselves. But experts hesitate to say for sure whether youre considerably more likely to develop Alzheimers if a family member has it.
Patrick Lyden, MD, neurology professor at Cedars-Sinai in Los Angeles, told The Mighty this idea has gotten into the public mindset likely due to news reports about the rare family-inherited dementias, but there isnt a definite one-to-one risk for Alzheimers. In fact, this is one of the most common misconceptions he encounters.
If you have one parent with Alzheimers and youre worried about your own risk, thats where we really dont know, Lyden said. In some cases those are hereditary, but a lot of times when youre talking about something thats so common, it might just be a coincidence.
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What Are The Stages Of Late
As late-onset Alzheimers disease progresses, the symptoms become more serious.
Early stages of the disease might include difficulty remembering conversations, names, or events. These early symptoms might also include changes in mood, depression, and a lack of interest in life.
As the disease progresses, these symptoms can become more pronounced and may include difficulty recognizing the faces or remembering the names of loved ones. In later stages, as the disease becomes more severe, symptoms may include difficulty in communicating, disorientation, confusion, poor judgment, and behavioral changes.
In the final stages of the condition, at its most severe, symptoms might include difficulty speaking, swallowing, and walking. At these later stages, a person may have difficulty feeding themselves or dressing, and they often require specialized care.
Alzheimers In Both Parents Ups Risk
Alzheimer’s risk doubles if parents suffer, reads the headline in The Daily Telegraph . It says a study of 111 families where both parents had Alzheimers disease found that the children had a 22.6% chance of developing the condition compared with the estimated 6-13% chance in the population as a whole.
This large study has shown that the offspring of parents who both have Alzheimers have a higher risk of developing the condition compared to the general population. Of the people who were involved in this study, 23% developed it themselves, and this risk increased with age to 31% in those over 60 and 42% in those aged over 70. The full extent of the risk is not clear, as, at the time of the study, most of these people were yonger than 70. It is important to note that the people in this study may have been particularly prone to Alzheimers, as they had been referred to a specialist centre, and therefore may have been more likely to have had a strong family history of Alzheimers.
This study highlights the heritability of Alzheimers, a factor that can be used in further research towards understanding the causes behind this complex disease.
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Cause #: Mild Cognitive Impairment
People who already have mild cognitive impairment may be at an increased risk of developing full-blown Alzheimers. A mild cognitive impairment doesnt necessarily impact a persons daily life in a major way. However, it can have some effects on memory, thinking skills, visual perception, and the ability to make sound decisions.
Scientists are trying to understand why some cases of mild cognitive impairment progress into Alzheimers. A
My Experience Caring For Parents With Dementia
For a while, my mom’s disease consisted of minor memory loss, and she was able to be a fairly active part of my dad’s care team after his surgery left him demented. However, as is to be expected, her condition worsened and I was soon coping with both of my parents’ odd and forgetful behaviors.
For example, their wedding anniversary was the day after Christmas. I would always bring to the nursing home tiny bottles of champagne and their 25th anniversary champagne glasses. I would also bring other treats and we would have a party. I also brought cards for them to give to each other.
I would sign Dad’s card to Mom, since he was unable to and didn’t really know what it was. Mom would sign her card herslef, but soon after she would forget what it was for. I would then pile the things into Mom’s walker bag and take her down the hallway to Dad’s room.
Generally, I’d have to drag Dad out of foggy sleep, sit him up and, with a big smile on my face, give them each their cards to one another, explain what they were for, read them with gusto, pour champagne, explain again what they were doing, let Dad fall back to sleep in his chair, and then bring Mom back to her room. Like a puppeteer, I would arrange bodies, move limbs, orchestrate a production. Each time I left for home feeling exhausted.
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What To Do If Someone In Your Family Is Diagnosed With Alzheimer’s
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Contact the Alzheimer’s Association . Find out about resources available to help you and your family. State and county agencies may also be able to help.
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Plan for the future. This includes legally designating someone to make health care and financial decisions for the affected person when he or she can’t.
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Investigate long-term care options. Nursing care is expensive, and finding a good place can take time. Start early.
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Take care of physical health. People with dementia who live a healthy lifestyle tend to progress more slowly to the later stages.
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Steer away from genetic testing. Even if you have the APOE Alzheimer’s risk gene, it usually doesn’t mean you will develop dementia later in life.
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Planning Tools And Resources On Ltc News
You can find many tools and resources on LTC NEWS to assist you in your research for a planning solution or help your family find the appropriate care for a loved one at the time of crisis.
To help you plan for the future costs and burdens of changing health and aging, LTC NEWS has put in place several resources, including:
- The Ultimate Long-Term Care Guide is an outstanding read to help you get a good overview of the topic area.
Find all the resources on LTC NEWS – Resources for Long-Term Care Planning | LTC News.
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