Alzheimer’s: I know I’m going to have early onset dementia

James Bexon was just 33 years old when he was told he had 20 to 30 years to develop Alzheimer’s disease.

His father was diagnosed at the age of 58, and in 2018 James underwent an NHS test which found he had a 99.9% chance of developing the rare genetic condition.

He was eligible for the test because of his strong family ties, but as a result, he wondered if it would be passed on to his sons, Elijah and Jacob.

Neither son inherited the gene that causes hereditary Alzheimer’s disease.

James was living in Tanlan, Gwynedd, when he began the testing process for hereditary early-onset Alzheimer’s disease.

His father died from the disease in late 2017, just before James’ tests began.

Half of his family developed the condition over the years.

James underwent multiple counseling sessions before his blood test in March 2018 to prepare for the possibility of bad news.

The results arrived 6 weeks later.

“The counselor had a trainee with her, so I read it on her face when she walked in,” he said.

“You half expect it anyway because it’s famous in the family. Obviously, it would be surprising if it was ‘You don’t understand.’

“I felt like that was the hand I was dealt, even if it was 50-50.”

He added: “The buildup of the protein amyloid that causes hereditary dementia shuts down memory and slows down all movements. It starts about 20 to 15 years before symptoms appear.

“Realistically, it may have already started, but I don’t know.

“Sometimes I think about it too much. Elijah is 5 years old and Jacob is 2 years old. As they get older, time flies.

“All of a sudden, you’re 40 years old, and actually, I’m going to be 50 years old not too long ago.

“Some people have parents who are in their 50s and 60s, and I want them to be like that too. I want my kids to have a proper grandpa. They have Gemma’s stepdad, but for me… Grandpa is missing.

“It would be nice if I could live as a grumpy old man until my 70s and 80s.”

James and his wife Gemma also faced the difficult decision of whether to test their two children for the gene while they were in the womb.

They decided to proceed with testing and both children came back negative.

Testing for rare inherited dementias, such as frontotemporal dementia and some forms of early-onset Alzheimer’s disease, is only available on the NHS in Wales and England.

Dementia UK nurse Jules Knight said: ‘Dementia UK statistics show that between 7% and 12% of people with early-onset dementia have inherited dementia.

“There are currently 70,800 people living with early-onset dementia in the UK.”

Drugs such as donamab, which trials have shown to slow cognitive decline, rely on early diagnosis, and private tests for other forms of dementia are not available on the NHS.

Mr Knight said there were concerns about private tests that only tell the risks, rather than NHS tests that can accurately identify genetic mutations.

“NHS tests are definitive in terms of whether you have a genetic mutation,” she said.

“Genetic risk variants, some of us may have that genetic variation, some of us may not, but that doesn’t mean you will develop it or you won’t develop it.” That doesn’t mean.”

She also said the NHS had provided extensive psychological support.

“If you are offered genetic testing, you should receive counseling both before and after,” Ms Knight said.

“Upfront is support as to whether or not to proceed with the test, its implications, and any support that may be required.”

For James, who now lives in Evesham, Worcestershire, the NHS test has given his family peace of mind.

“We’re not going to have any more children, so we know we’re done with hereditary Alzheimer’s disease.

“For me, it was about trying to stop the progression of this disease in my family. There’s only so much you can do, and we did everything we could.”