One in 50 people ‘almost guaranteed’ to develop newly discovered type of genetic dementia, scientists warn
ONE in 50 people could be at risk of a new type of genetic dementia, according to a study.
Researchers found people carrying two copies of the APOE4 gene mutation are “almost guaranteed” to develop Alzheimer’s in old age.
Tests showed 95 per cent had signs of the disease by age 65.
Two per cent of Westerners are estimated to have two copies of the gene.
They include Avengers actor Chris Hemsworth, 40, who stepped back from work to spend time with his family after discovering his dementia risk.
Around 25 per cent of people carry one copy, which roughly trebles the risk compared to having none.
APOE4 genes were already known to be a danger, but scientists led by the Sant Pau Research Institute in Spain now say the link makes Alzheimer’s pretty much a certainty.
Neurologist Dr Juan Fortea said: “This gene has been known for over 30 years and it was known to be associated with a higher risk of developing Alzheimer’s disease.
“But now we know that virtually all individuals with this duplicated gene develop Alzheimer’s.
“This is important because they represent between two and three per cent of the population.”
People with two copies of this gene are almost guaranteed to develop Alzheimer’s if they live long enough
Professor Tara Spires-Jones
Tests on 273 people with double APOE4 showed that, by age 55, nearly all already had early chemical signs of Alzheimer’s disease.
Spinal fluid tests showed that, by age 65, more than 95 per cent had “abnormal” levels of a protein believed to be a cause of dementia.
Writing in the journal Nature Medicine, the researchers said sufferers began to get symptoms at 65 – around a decade earlier than typical Alzheimer’s patients.
Dementia is the leading cause of death in Britain and around a million people have it, with at least six in 10 cases caused by Alzheimer’s disease.
Experts said understanding this genetic cause as a new form of the illness could help improve diagnosis and treatment.
Professor Tara Spires-Jones, from the UK Dementia Research Institute, said: “This study adds compelling data to suggest that people with two copies of this gene are almost guaranteed to develop Alzheimer’s if they live long enough.
“It highlights the importance of more research into understanding how genes change the susceptibility of our brains to Alzheimer’s disease as we age.”
What are the early symptoms of cognitive decline?
WE all notice a natural decline in memory and thinking as we age.
This will be more pronounced in some people, as they experience memory and thinking problems that are mild but still noticeable.
This is described as mild cognitive impairment (MCI). Unlike dementia sufferers, people with MCI can still get on with day-to-day life.
Research suggests that two out of 10 people over the age
of 65 have MCI, according to Alzheimer’s Research UK.
About one in 10 people who’ve received an MCI diagnosis will go on to develop dementia.
Symptoms of MCI include:
Memory – Misplacing items or having trouble
remembering recent conversations.
- Attention problems – finding it difficult to concentrate,
e.g. while watching a TV programme or carrying out
duties at work - Disorientation – confusion about time, date or place
- Thinking skills – problems with planning or completing
tasks, e.g. managing money, or cooking a meal - Problems with communication and finding the right words
- Mood and behaviour changes – becoming irritable, anxious,
or feeling low
These symptoms may affect someone with MCI all the
time, or they might come and go.
There are steps we can take to keep our brains as healthy as possible. These include:
- Not smoking
- Doing regular physical activity
- Staying mentally and socially active
- Eating a healthy balanced diet
- Limiting the amount of alcohol we drink
- Having your hearing checked regularly
- Keeping blood pressure, blood sugar and cholesterol
levels in check