Saturday, October 29, 2022

Genes that may help you survive the Black plague, but not your own immune system

An article by Science discusses research that suggests certain genes helpful in surviving the Black Plague centuries ago may be increasing the risk for modern autoimmune diseases. This research was led by Mihai Netea in Romania. Netea compared genomes of ethnic groups that survived the Black Plague and those that did not experience it. They were able to pinpoint genes on chromosome 4 that are critical to the immune system. These genes found in the survivors code for proteins with receptors that are very responsive to the Black Plague bacterium, Yersinia pestis. As a group, those who did not experience the Black Plague often lacked these genes. It was hypothesized that these contributed to an over active immune system that was vital in surviving a deadly pandemic. 

However, this immune system is not as helpful today. These receptors have started triggering immune responses to an individual's own body and leading to long term autoimmune disorders. Today, those who have the genes found in Black Plague survivors are often at a higher risk to develop Crohn's disease, rheumatoid arthritis, lupus, and other autoimmune diseases. This research demonstrates the fascinating effects that passing on genes can have over generations. It also brings up the idea that the traits which are positively selected for are very dependent on the time and environment in which they exist.


  1. Hmm that's very interesting research, its weird to me how genes that helped us in the past would be harmful now. This is an interesting idea of tradeoffs in traits, an overactive immune system is able to defend against black plague but may be so responsive that an individuals own body can trigger it into thinking a disease is there. I guess over time the prevalence of these genes will change to match how well they help humans survive in whatever situation we are exposed to over time.

  2. This makes me wonder if the bacteria that causes the black plague has a similar makeup to bacteria occuring in the organs of these individuals in which these autoimmune diseases tend to attack. Perhaps this helped with their immunity.