Chris Graham, 39, was named with the condition when he was only 34 years old.
His brother Tony is also pompous by the disease and although is only four years old than Chris, he troubles round-the-clock care.
Chris and his wife Vicky joined hosts Holly and Phil on This Morning to talk back his diagnosis and what it means for the future.
Chris told them ‘terrify bells’ started raining with his brother fell ill — which prompted him to own a blood test for a gene which can cause early onset Alzheimer’s.
“When I bring about out about the tests and I found out I had it I was quite relieved in a way,” he said.
He told the comperes it explained why he tended to forget things.
Chris’s sisters do not have the broken gene, but his grandfather, aunt, cousin and father all suffered with the rare acclimate.
Vicky said: “He [Chris] told me he had this gene confirmed. We neutral thought that was it.
“It wasn’t until the day after I found out I was expecting Dexter that we realised the shell had gone off. I googled it because I was curious.”
Vicky said she thought the conformist age for early onset Alzheimer’s was around 55 but the couple were swore there might be a maximum of seven years before the condition memorandum ofed hold.
The couple have a son called Dexter, who has a chance of inheriting the gene.
In any case the family said they have to wait until Dexter is 18 to exam if he carries the gene.
“We have to wait now,” added Vicky. “Until he decides he stand in wants to be tested.”
Chris has completed a 16,000-mile, year-long bike cheat around the coasts of Canada and the United States in a bid to raise money for Alzheimer’s Investigate UK and ABF The Soldiers’ Charity.
He has raised around £50,000, with the help of Vicky, who helped him voyage the route.
Phil, who said Chris had remained ‘very positive’ said: “Your deterioration has slowed down and that is perchance down to your supreme fitness.”
Chris added: “I think we’re prevailing to get away with it.
Alzheimer’s Research UK said: “Several genes possess been found that play a role in the development of rare familial Alzheimer’s.
“Clangers in these genes (called mutations) can cause a build-up of a toxic protein reasoned amyloid in the brain.
“If someone has a strong family history of Alzheimer’s at a youthful age, genetic testing may be suggested and genetic counselling may be offered to close relatives.
“In the limitless majority of cases, the cause is still unclear. It is likely to be a combination of our age, lifestyle and genetic personality.”
What is Alzheimer’s disease? Condition which triggers memory damage is form of dementia