Testing: Victoria Huntley wanted to know if she’d inherited a gene which meant she would develop early-onset Alzheimer’s
Fit and healthy, and then aged 36, Victoria Huntley faced an unenviable dilemma.
Be tested to see if she’d inherited a gene which meant she would develop early-onset Alzheimer’s disease — or live her life in ignorance, knowing it could strike at any time.
The disease had blighted the lives of three of her relatives, with her mother, grandfather and great-grandmother all dying young from Alzheimer’s.
Her mother first showed signs of the disease at the age of 34 and by her early 40s was unable to look after herself. She spent the last 12 years of her life in a nursing home, and for eight years — until her death at the age of 56 — she was tube fed and unable to speak.
Victoria’s great-grandmother had died at 36, and her grandfather at 42.
‘I was 19 when Mum started making mistakes,’ says Victoria, now 48, a former care worker from Beckton, East London. ‘She’d make a cup of tea and then forget about it. She also started doing odd things at work — at a hairdresser’s — pulling people’s hair and pinching them.
‘Initially we thought she had cancer but then we realised it was dementia.’
Shortly after her mother’s death 12 years ago, Victoria and her three siblings were offered the option of being tested to see if they had inherited the genetic mutation which causes early-onset Alzheimer’s.
‘For me, it was an easy decision,’ says Victoria. ‘I wanted to have the test because I was sure I would have the faulty gene. I wanted to be aware of what was going to happen to me.’
Victoria, who is married to Martin, 52, a bus driver, and has two children, Leanne, 28, and Craig, 26, and six grandchildren, had six months of counselling to prepare her.
As many as half of those considering genetic testing decide not to go through with it in the end, according to the Alzheimer’s Society.
Testing may be offered to those with a first degree relative (such as a parent) or second degree relative (grandparents, aunt or uncle) with a known genetic form of Alzheimer’s, or if a pattern of dementia in family members under 65 suggests that it’s an inherited disease.
Divisive: As many as half of those considering genetic testing decide not to go through with it in the end, according to the Alzheimer’s Society
‘Having a predictive genetic test may remove uncertainty and allow you to plan for the future,’ says Dr Doug Brown, the Alzheimer’s Society’s director of research and development.
‘It may make you eligible for a trial of a new drug or open up opportunities such as pre-implantation diagnosis — where embryos are screened for faulty genes before they are put back in the womb.
‘However, it can also be a very stressful process. If you are found to have the mutation, this knowledge cannot then be unlearned. There are currently no treatments that can prevent or slow the progression of any form of dementia — inherited or otherwise.
‘This is why predictive testing is only done with expert genetic counselling — both before and after testing. The result will usually affect other family members, too, some of whom might not want to know the outcome.
‘Not knowing leaves room for hope, whereas the knowledge of a positive test result cannot be reversed,’ adds Dr Brown.
A month after having her blood test at the National Hospital for Neurology and Neurosurgery in London, Victoria received the news she feared: she had inherited the faulty gene called APP.
It meant she was almost certain to develop Alzheimer’s at some point in her 30s, 40s or 50s. After learning the news, she admits she ‘just fell apart’.
‘I was always convinced I would have the gene — but to have it confirmed was a real blow.’
Victoria’s 43-year-old brother also tested positive for the gene, one of her sisters doesn’t have it, and her other sister has decided not to be tested.
Dementia mainly affects the over-65s, but more than 42,000 younger people have the condition. An unhealthy lifestyle increases the risk, but in patients under 65, faulty genes are more likely to be to blame.
‘Among people with young-onset Alzheimer’s disease, about one in ten has a very strong family pattern of inheritance,’ explains Dr Brown.
Familial Alzheimer’s — which Victoria’s family has — is caused by a fault on one of three genes: APP, PSEN-1 and PSEN-2.
People who inherit one of these three mutations will definitely develop the disease, usually before the age of 60, and there is a 50 per cent chance of passing the gene on to a child.
Any form of dementia treatment can only slow the symptoms, not cure the condition. They include Aricept, which prevents the breakdown of a brain chemical called acetylcholine, which is important for memory, or acetylcholinesterase inhibitors (people with Alzeheimer’s have been found to have low levels of acetylcholine).
The first signs of dementia in Victoria occurred when she was 40. ‘I messed up an old lady’s medication,’ she says. ‘Thankfully it was nothing too serious, but it upset me and I knew it was time to give up my job.
‘Today, I can stand looking at the kettle for 10 minutes, not knowing why I am there; or I put on clothes back to front. It’s difficult to get upstairs because my spatial awareness is poor, so we have bright stickers on the steps so I can see them.
‘I can’t go on my own any more, because I wouldn’t be able to find my way home. But I’m not scared of what lies ahead. By the time it comes, I won’t know what’s going on. It will be harder for Martin and the children.’
In the meantime, the family are determined to make the best of the time they have.
‘We have barbecues in the garden all the time, even when it’s raining,’ says Victoria. ‘We think, “Sod it, why not!”
‘I’m happy I’ve had the test, but at this moment I wouldn’t recommend it to my children because having that information does change things.’
Join Dementia Research matches researchers and people who want to participate in dementia research. joindementiaresearch.nihr.ac.uk