'I face 50/50 chance of getting Alzheimer's in my 50s just like my mum'

A man whose Coventry family were the first in the world to be diagnosed with hereditary early-onset Alzheimer's has shared his fears about developing the illness in his 50s. John Jennings was told that he had a 50/50 chance of facing the same fate as his mum Carol.

Carol Jennings spent years at the forefront of research into early-onset Alzheimer's Disease. It all started when the Coventry woman penned a letter to the University College London (UCL).

In the 1980s, it was widely thought Alzheimer's Disease had no familial link, but Carol urged UCL to explore a hunch that her father and his four siblings' diagnoses were linked. Years later, her fears were confirmed after a mutant gene was discovered by Alison Goate, in what she described as a 'eureka moment.'

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Carol was faced with the devastating reality that she had a 50/50 chance of inheriting Alzheimer's, and if she did, her two children, John and Emily, would face the same risk of developing the illness in their 50s. She said at the time that she 'did not see the benefits in knowing' and that she could 'live quite happily with the doubt that I may get it.'

Although Carol chose not to test for Alzheimer's, her health started to deteriorate as she entered her 50s. John said watching his mum become a shell of her former self was a 'big shock.'

Speaking to CoventryLive, John said: “We always knew mum was a 50/50 risk because the gene had been found in our family, but me and my sister do not really remember what our grandad was like before because we only remember him being ill as he had already been diagnosed by the time we were kids. Neither of us realised what it was like going from being well to being unwell because we had only ever seen my grandad unwell, and so when mum started getting ill that was definitely the biggest shock for us.”

Researchers at UCL identified a gene in 1991 that all her affected family members shared. A mutation to the Amyloid Precursor Protein (APP) gene means too much amyloid protein is built up in the brain, which clumps together to form plaques and causes brain cells to die thus causing Alzheimer's Disease.

John, who was raised in Coventry but now lives in Edinburgh, has been told that he has a 50/50 chance of developing early-onset Alzheimer's. He said the one thing he fears the most is losing the connections he shares with his loved ones, like his mum Carol did.

He said: “I guess my biggest fear is losing those connections to the people around me because I have got people who care about me a lot, but if you do not feel it, you are alone in a scary place. I think that is the thing that I am scared of.”

It is something which John said made his strong-willed mum 'very isolated' as she battled Alzheimer's in her 50s. Carol died in March this year leaving behind a legacy of change which the 39-year-old vows to continue in the hope that there will soon be 'big breakthroughs.'

John said: “We have no control over whether we have it or not. I think me and my sister deal with it in different ways but we are both of the opinion that if there is anything we can do about it all then we should do it, and so I guess that is why I have decided to carry on taking part in research like mum did because I am really hopeful that they are going to have some really big breakthroughs.”

Siblings John and Emily now face the agonising choice about whether they should be tested to find out if they carry the gene, but said they will do so 'when the time is right.' John said: “At the moment, we do not know.

“I think me and my sister said that we probably want to have tests at a similar sort of time like if one of us has the test, the other one will probably want to have it soon after. I think we are both just going to keep pushing on through and then we will have it when the time is right but it is probably not that time just yet.”

After years of setbacks, two new drugs that slow the decline of Alzheimer's Disease are set to be licensed in the UK. John described the new developments as 'exciting.'

He said: “You can have the test and we would know whether we are going to get the disease or not, theoretically they could start us on those drugs earlier so I am quite confident that if they are able to start clearing those plaques a lot earlier then it probably would slow down the disease. I think if the NHS does license them it is really exciting.”

Watch The Jennings Vs Alzheimer's on Monday, May 13 at 9pm on BBC Two and BBC iPlayer.

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