The APOE4 gene is associated with an increased risk for development of the most common form of Alzheimer’s disease (AD) (1, 2). Scientists recognized the significance of the APOE4 gene almost 25 years ago, but the tests for it have a big problem – they often fail to predict the future correctly. A substantial fraction of persons harboring APOE4 genes never develop AD dementia while a large number of people without it do (2). When it comes to AD our genes are not necessarily destiny.
Environmental and behavioral factors such as diet, exposure to toxic substances, personal health habits, stress, how much exercise you get and education all influence your risk for future dementia (2). However, their potential to change the risk of developing AD and other conditions have been largely overlooked. That is about to change.
Major scientific efforts are underway to correlate genomic DNA sequences with personal health records to yield more comprehensive and informative data sets (3). Capturing a broader array of information embedded in medical records using new generation natural language processing programs may help scientists reveal the elusive extra-genetic instigators of many chronic conditions. Advances in DNA sequencing technology and large database processing have now converged to make the time ripe for such efforts in AD research.
Detailed studies of Catholic sisters revealed that the idea densities expressed in autobiographies they wrote when entering religious life strongly predicted whether or not they would develop AD decades later (4). This suggests linguistic assessments of writing samples combined with comprehensive health record data may provide what genetics alone cannot – readily attainable sentinel indicators for future dementia development risk. Several lines of evidence suggest it is possible to decrease the threat for developing AD (4, 5). The ability to recognize persons most at risk years or decades before dementia becomes clinically evident would revolutionize AD research. However, no miracle cure for AD is imminent and such advance knowledge would also empower individuals to take actions to improve their chances to evade dementia. Converging technologies could catalyze an immensely practical advance in the struggle against AD in the form of an App.
New technologies convey both benefits and risks. The history and developing situation with APOE genetics is particularly interesting. The Genetic Information Non-discrimination Act (GINA) of 2008 bans using genetic data as a basis to deny health care insurance or employment (6). However, that law has some gaps. In most U. S. locations underwriters of long-term care insurance may use APOE genotypes to set rates or deny coverage. Genes are not destiny, but a person known to harbor APOE4 genes may discover finding affordable long-term care insurance is more difficult because actuaries know the odds of AD dementia emerging in such applicants are increased.
Let’s say we have an App that is proven to be a reliable mechanism of predicting AD risk. Unless we devise rules and regulations to limit its use, long-term care insurance applications may soon include providing a brief autobiography. And there is more; GINA covers genetic sequence information, not predictions based on writing samples and other data extracted from medical records. The coming information surge could turn out to be an insurance actuary’s dream.
The good news is that converging technologies seemed poised to propel AD research forward and help people evade dementia. We will have to consider the implications of new found capabilities carefully. Don’t worry about the actuaries. They will still beat us every time.
(1). L. Spinney. 2014. Alzheimer’s Disease: The Forgetting Gene. Nature 510:26-28, 4 June 2014. http://www.nature.com/news/alzheimer-s-disease-the-forgetting-gene-1.15342
(2) National Institute on Aging. Alzheimer’s Disease Genetics Fact Sheet. https://www.nia.nih.gov/alzheimers/publication/alzheimers-disease-genetics-fact-sheet
(3) D. J. Rader and S. M. Damrauer. 2016. “Pheno”menal Value for Human Health. Science 354:1534-1536, 23 December 2016. http://science.sciencemag.org/content/354/6319/1534.full
(4) J. A. Mortimer et al. 2005. Very Early Detection of Alzheimer Neuropathology and the Role of Brain reserve in Modifying Its Clinical Expression. Journal Geriatric Psychiatry and Neurology 18(4):218-223. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1405917/
(5) G. Kolata. 2016. U.S. Dementia Rates Are Dropping Even as Population Ages. The New York Times, 21 November 2016. http://nyti.ms/2eYS0zC
(6) National Human Genome Research Institute. The Genetic Information Nondiscrimination Act of 2008. https://www.genome.gov/24519851/