Genetic testing for dementia

Inherited factors alone only very rarely explain why some people develop dementia. When dementia starts before the age of 60 it may occasionally have a genetic cause which can be tested for. Some people with dementia, and their relatives, worry that dementia may run in their family and want to know more about genetic tests.

Some of the carers we interviewed were in favour of genetic testing for a subset of young onset Alzheimer’s disease. This was usually because they believed that by finding out before any symptoms appeared, it might be possible to prevent or slow the course of the disease. A man who had cared for his wife until her death had changed his mind and would now consider testing to gain peace of mind for his new partner and himself. Unlike most other parents we talked with, who thought that children should make their own decisions about testing, he said that if his children were small he would have them tested. In situations where genetic testing is offered, the family should be offered counselling by a specialist geneticist who can think through the pros and cons of testing with them.

Is in favour of testing if early detection might allow for treatment that could slow the course of the disease.

Gender Male

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We have, its something that my daughter and I have talked about because, you know she, she said to me quite recently Well, Mum, has got dementia, my grandmother had dementia, we think almost certainly her mother also probably had it in the last stages of her life, maybe I shall get it. so, certainly we, weve kind of thought whether this might be a, this might be something that, would be helpful to the female side of the family.

I think the research suggests that you know over the next twenty or thirty years we are, we are going to, we probably are going to come up with.

Something which will if not cure dementia at least will, can alleviate it dramatically. And therefore anything which can make the younger generation more alert to the possibilities of developing it and, and therefore can take any actions, which might alleviate the early stages seems to me a good thing. So on the whole I think I’m probably rather in favour of, genetic testing. Yes, I think on the whole I’m in favour of it and I think my daughter is also probably too.

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Has changed his views about tests since looking after his wife. Is now planning a test for prostate cancer to reassure himself and his new partner.

Gender Male

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I wouldn’t mind it, yeah. Yeah I wouldn’t mind it because I, I have changed my views, I must admit previous, previously to, looking after [name] I would have said I Don’t want to know anything. But I think I’ve only changed my views now because I’ve met somebody else who as I said before, her husband died of prostate cancer, so I’ve, I felt prepared to go and have that test just for their peace of mind. I mean it would give me peace of mind obviously, but I was thinking more in that direction. So yeah I, I think I would now, if somebody said, Well you know theres a test going for so and so, I would probably go for it.

Would you want your children to be tested?

Are we talking about grandchildren or tiny children? Well even if Id like my family tested, theyre at an age where they make their own decisions but, usually you know theyre, I would say Yes, but then they would have to make their own decision. If it was a, a small child then Id have it done, now. Because theres so many things that can be done in the early stages, so instead of you being seriously ill or dying you can be made better. So yeah I think it’s a good idea now to have these different tests, and that’s why I’m having the one as I’ve already said.

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Others were less optimistic about prevention, or concerned about the effect of genetic testing on insurance premiums, but thought that adults might need to know when they were making decisions about whether to have children (pre-conception screening). A woman who said that she would not have wanted to know when younger and working, thought she might want to know now that she was planning her retirement. Another woman who had cared for her mother said she would want to know for herself so that she could make plans and spare her children what she had to go through with her mother, but would not encourage them to be tested.

Says she would not have wanted testing when younger but might be interested now she has retired.

Age at interview 60

Gender Female

Age at diagnosis 80

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I wouldn’t, mind, but I think perhaps I might leave it till, I’d probably leave it till about now, you know, now that I’m retired because I said I’m now beginning to think about my old age. If I know I’m going to have, get Alzheimer’s then it will influence my planning for my old age. But I’m not sure that I’d necessarily want to know when I was younger. But I wouldn’t mind, I mean it wouldn’t make a great difference now because while I’m not working and not having to get jobs, and I’ve got an income coming in. So yes I’d probably quite like it for me.

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If preventative treatment becomes available most people would favour testing. Several carers could not see the point of testing when it wasnt clear what could be done with the information. Some thought that knowing that one would develop Alzheimer’s at some point in the future could be a sword of Damocles, causing people to feel hopeless, although another woman pointed out that one could be knocked over by a car in middle age and never develop the predicted condition.

Cannot see the benefit of repeated testing if there is no preventative advice or treatment to offer people who are found to be at risk.

Age at interview 62

Gender Female

Age at diagnosis 61

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The stem cell research doesnt cause me any concern at all. I dont agree with genetic engineering for things like babies but I think if we can find ways of engineering illnesses and genetic defects that cause, may cause things like dementia or muscular dystrophy or whatever the other awful things are then I have no, no hang ups about them pursuing that line of research at all.

Blue eyed, fair-haired white babies, yes I would have concerns about that. Or boys or girls, yes I would have concerns about that. But not, not otherwise I dont look on it as a Frankenstein thing, I look on it as progress. I mean weve progressed ever since man was created. This is just another way that we are able to progress. Thats just, thats just my opinion anyway.

Well I think thats got to be a personal matter. I know that [my partner]s daughter has said that her brother has said that even if there was genetic counselling he wouldnt go for it because unless, I think the good thing about genetic counselling is if youre aiming to have children and you want to know whether theres anything in your family that youre likely to pass on.

It can be valuable then. And then I think if you, if you are in danger of developing something in later life about which nothing can be done I really dont see the point, because all youve got is the Sword of Damocles hanging over your head. Knowing that further down the line, X number of years youre going to start developing, I mean lets just say dementia for one thing, or cancer or, I mean were all going to die of something but do you want to know that thirty years on youre gonna develop dementia?

I dont want to know I, and if I went to see a geneticist and I had the tests and they said Oh yes youve got all the signs that youre going to develop dementia, it would just, I might as well put a gun to my head and commit suicide now.

Because I think unless you know that something can be done about it, and were not that far on enough yet to know that. There is nothing we can do to prevent dementia in spite of them saying use it or lose it You know I have a living proof here of somebody doing a degree and then losing it straight away, so it doesnt protect you, it might help in some cases but nothing can protect you against the onset of it, as far as we know, unless its caused by alcohol abuse or boxing or something like that and thats a physical cause.

So no I think the genetics, the fact that we can maybe identify the markers is dangerous if we cant give anybody any hope. So I think its a very murky pool at the moment. I think when were further down the line in a few years time and theyve got maybe things they can do about it, yes, that would be good. But at the moment they cant for dementia, so whats the point!?

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People sometimes have a strong sense that they are a likely candidate for a disease, and that testing would just confirm what they suspect. One woman, who had cared for her mother, had a theory about personality type, which she believed made her particularly vulnerable.

Can see pros and cons to having a genetic test for dementia, just as she could for cancer

Gender Female

Age at diagnosis 80

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You mean to find out whether they’re likely to get it? Well my immediate thought was good, that’s great and then I think do I want to know. I mean I really would like to know, I mean I’ve always said if I’ve got cancer and it’s terminal I would want to know. So in a way I would want to know, but on the other hand if I’m going to get it anyway is it going to make any difference?

I mean already I’m convinced I am going to get it, to be honest, and, not just because of my mother but because of, I don’t know, I have theories of personality type and all sorts of things which may be completely unfounded but I’m sure I’m going to end up with it. So yeah I suppose it would be interesting to have it confirmed.

I once found a lump and I thought if I found a lump I would go to the doctor straight away but I didn’t because for a little while I just pretended it wasn’t there, and I went in and it was nothing and I haven’t got it now. But, I think, I think it’s a good thing, yes genetic testing I think it’s nice to know you’ve got the choice perhaps psychologically, it would be nice to know that you have got the choice of finding out if you want to.

Like a lot of things, you know if you’re on a diet and you know you can’t eat chocolate you immediately want it don’t you. But if you’re on a diet and you can eat as much chocolate as you like then you’ve got the choice, it would be nice to know the choice was yours to find out if you wanted to. But whether I would actually find out.

I probably would actually, I probably would want to find out. But whether I’m going to get it or not going to get it I still have a vested interest in finding out what research is going on and what things…

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Simply knowing that a test is available can cause a dilemma. Some carers were uncertain whether to tell adult children that it might be possible, since they might prefer not to have known. In some cases it would not be known if the disease was a inherited type unless a post mortem examination was performed. A woman caring for her second husband was uncertain how to deal with this information with her step children, and wished she knew where to turn for advice.

A post-mortem may reveal fronto temporal dementia, with implications for her husbands children. She thinks it will be a very difficult decision for them to make.

Age at interview 61

Gender Female

Age at diagnosis 70

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Well its something which we discussed at the meeting on Friday, theres a possibility, theres a, the consultant, the two local consultants in sort of dementia and Alzheimers, theyre pretty sure that what [my husband] is suffering from is a fronto temporal lobe vascular type dementia.

But, there is a vague possibility still that there could be something genetic in it. And the only way to be sure is with a post mortem but because this area does not have a teaching hospital or a specialised interest in dementia they wouldnt normally request to do a PM. And if we wanted it done we need to set it up obviously before he dies.

But thats something, which for myself I mean is, the dementia has hit him and the cause isnt terribly relevant but the implications for his family are still there. And how Im going to broach that with them is, is a biggy. I dont know how you know Do you want your dad to have a post mortem so youll know if youre going to get this disease? Put at its bleakest. So that, is something Im working on at the moment. About as ethical as it comes I guess.

I feel if any of them want it then yes I think, I think it has to be for them to decide. I mean I, I dont mind, I dont have any real worries about it. So it is really I think for them, for them to decide, if I decide to give them the option. Perhaps I need to talk about it more. I dont know who with really.

My, my kids are brilliant, theyre very supportive but I think they would have to say Well its, its for his children to decide. Because I mean they just see as , the cause of this horrible thing is not really relevant, we just deal with what weve got.

The local consultant, he was very, very up front about you know what it entails and whether they would want to know and you know whether testing, I suppose if I gave them the option, maybe if we had the post mortem then they would have to look at the option of taking it further for themselves as individuals.

But I suppose once youre faced with that sort of option it does put a lot of stress on you, doesnt it? And then on the other hand if anything developed later, two of his children I know are still considering extending their families, maybe they need to know before that, before that happens. Maybe if theyve got that knowledge then they will make different decisions, I dont know! Theres one couple, I mean theyre both in their 40s and they only have one child. I think weve more or less been reassured on this point last, last autumn.

Because my younger stepdaughter had read something about frontal lobe dementia and it being like a 50% chance of this particular gene being passed on and she asked me to find out more about it. Which I did and we got another assessment of from the doctor who is based in north. And he came back again with the vascular dementia probably caused through smoking, he hasnt smoked for thirty or thirty-five years but he said that doesnt matter it was still an option. But he felt that the likelihood of it being one of the other frontal lobe ones was minimal.

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