In the US, there are 5.5 million Americans with Alzheimer’s — a disease defined by the progressive deterioration of brain function, most often affecting thinking and memory, that typically begins during middle or old age. Among the 5.5 million patients, the vast majority are at least 65 years old, while an estimated 200,000 suffer from what's known as early-onset Alzheimer’s.
Assessing someone's lifetime risk of contracting the disease is of concern not just to patients and families, but also healthcare providers. Alzheimer’s risk factors are notoriously hard to identify, but getting that information as early as possible can help prepare patients and families to manage the disease, and in many cases support preventative efforts.
Gaining more insight into a patient's risk may soon become remarkably easier: researchers from the University of California San Diego (UCSD) School of Medicine and University of California San Francisco (UCSF) have created a genetic test that can calculate a patient's age-specific risk of Alzheimer’s.
The method looks for 31 genetic markers, gathered from over 70,000 individuals, including patients suffering from Alzheimer’s as well as healthy elderly patients. Scientists based the test on background genetic variations which, individually, have a tiny influence on Alzheimer’s — but collectively, their effect is substantial enough that they can accurately predict an individual’s risk of developing the disease.
“Preventing the development of dementia symptoms is the holy grail of Alzheimer’s research but to succeed we first need accurate methods to predict who is most likely to develop the condition. This study’s approach was fairly successful at predicting the likelihood of someone developing dementia over the coming year, but needs to be tested further in mixed, non-US populations,” said James Pickett, head of research at Alzheimer’s Society in a report published by The Guardian.
It should be noted that scoring high on this genetic test doesn't automatically mean someone will develop Alzheimer’s. Nor does it imply that scoring low means someone would be considered immune to the disease. Genetics is one of several factors that determines a person's risk for developing any disease, including Alzheimer’s.
"From a clinical perspective, the [test] provides a novel way not just to assess an individual's lifetime risk of developing Alzheimer’s disease, but also to predict the age of disease onset," said senior author Dr Anders Dale, of the University of California San Diego School of Medicine.
While we have yet to find a viable treatment for the disease, experts believe that we are getting close. To that end, they assert that once a cure is found, it would still need to be administered as early as possible in the course of the disease, to ensure that damage done to the brain is at a minimum.