Channel 4 News Science Correspondent Tom Clarke meets the world's largest community with inherited Alzheimer's. The group, in a remote Colombian village, is at the centre of groundbreaking research.
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Her symptoms are the same as for millions of Alzheimer's sufferers around the world but Ophelia's disease is very different; she was always going to get it. She carries a mutated gene which has been in the family for years.
Since their mother's death, older sister Aura has run the household. She told Channel 4 News that of 16 brothers and sisters, eight inherited the disease and four have died so far. Her life now revolves around providing Ophelia and her brother Gustavo with full-time care.
"For me it's very hard. Because you think for who it's more difficult for - for oneself or for the sick ones. Maybe we can say that they don't feel anything. But the truth is that you don't know what they feel," Aura said.
Maybe we can say that they don’t feel anything. But the truth is that you don’t know what they feel. Aura, Alzheimer's carer
In and around their town of Don Matias, they are not the only family suffering. As many as 5,000 people in Antioquia carry the gene.
If they have children, half will inherit the gene. Usually the disease strikes at the age of around 49 years - here the elderly watch the young die of Alzheimer's.
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It is thought a single Basque settler brought the disease here in the 18th century. His direct descendents carry what is called the Paisa mutation, a nickname given to Colombians from these hills.
The remoteness of this region is the reason the mutation has survived. But after nearly 300 years, the isolated suffering of these families has come to attention of the outside world because the mutation they carry could be the key to preventing Alzheimer’s in millions of sufferers around the globe.
Dr Francisco Lopera, the Colombian neurologist who discovered the mutation, has worked for 25 years to gain the trust and support of the families in Antioquia. He believes his research is significant.
"The families know that if they get involved in disease research here, they are contributing globally. They not only do it in order to find a solution for their problem, but also to help other people," Dr Lopera says.
A new front in the battle to prevent Alzheimer’s
Because there is no predictive test for the common form of the disease, drugs are only given once symptoms are apparent but by then damage to the brain may be irreversible. Yet in Colombia a simple genetic test can reveal exactly which family members will develop the disease, decades before it strikes.
"This gives us an incredible window of opportunity to look at the very early stages of this disorder," says Dr Adrian Ivinson, who coordinates Alzheimer's research at Harvard University in the United States. He went to Colombia to see for himself the potential these families have to help researchers shed new light on the disease.
"It gives us an opportunity to try any future medications, any future drugs in a person whose brain is not so badly damaged," he continued.
Five years is too early for us to expect a cure for the disease, but it is possible that in five years it could be delayed. Dr Lopera
While research continues into new drugs, Dr Lopera and his colleagues are about to embark on the first clinical trial aimed at preventing Alzheimer's. In collaboration with two other US institutions and an as-yet undisclosed drug company, they plan to give an existing Alzheimers drug to 300 family members. Though the drug failed in trials to slow, or reverse existing Alzheimers the hope is it might work to prevent, or delay the disease developing in the individuals with the mutation.
"It is probable that five years is too early for us to expect a cure for the disease, but it is possible that in five years there might be interesting treatments that will delay the disease. And, in the medium term, it may be possible to find a cure, I don’t know how long it will take, but that is the hope we have," Dr Lopera concludes.
In all probability the cure is a long way off. But the contribution these families have already made could lead to major advances in understanding Alzheimer's. Anything that delays the progression of the disease, will improve the lives of future generations here. And any development would also benefit the one in ten of us that have a chance of developing Alzheimer’s in our lifetime.