The New York Times has a gripping article and video report about how a family in Colombia may be the key to unlocking the neuroscience of early-onset Alzheimer’s disease, one of the most devastating forms of degenerative brain disease that can strike as early as the 30s or 40s.
Alzheimer’s disease is a form of dementia, meaning that the mind and brain decline quicker than would be expected through normal ageing, but usually it is a condition of the old.
Most dementias are not thought to have one specific cause and are put down to a lifetime’s ‘wear and tear’ combined with different levels of risk from a number of genes.
In contrast, there are some forms of dementias, known as early onset dementias, that typically strike in middle-age and are much more likely to be due to mutations in single genes or mutations in only a handful of genes.
While we understand the genetics of these conditions quite well these days, it is still not understood why they cause the terminal and rapid decline of the brain.
The New York Times article discusses research from my own university, the Universidad de Antioquia, because one family in the Antioquia region of Colombia has the highest known rate of early-onset dementia in the world.
Genetically, the Antioquia region is very interesting and is known as a ‘population isolate’ because there has been very little influence on the gene pool from outside the region for about two centuries, largely due to the imposing mountains for which the area is famous.
The population originates with settlers from the Basque region of Spain who intermarried with native people (interestingly, almost entirely Spanish men with native women) while subsequent generations largely intermarried with each other. A recent study of the region shows very little change in genetic variation across the region and little change in common surnames for 200 years.
In effect, the region is like a giant ‘petri dish’ for population genetics and this means it is a lot easier to link genetic influences to specific disorders of the mind and brain. The New York Times piece features the work from the neuroscience department while my department, psychiatry, have completed much work on the genetics of bipolar disorder for the same reason.
The article describes both the potential of the research and the challenges of working in the region and is a fantastic account both for its scientific content and its humane approach to the issue. If you do nothing else, however, watch the short video report which is a powerful piece of scientific film-making.
Link to NYT piece ‘Alzheimer‚Äôs Stalks a Colombian Family’.