The Black Death epidemic, which caused millions of deaths in the mid-14th century, is believed to have resulted in a genetic mutation that helped survivors fight off this bacterial disease.
According to a recent British study, this genetic variation is still present in some people today.
The modification of the ERAP2 gene is believed to help carriers fight respiratory diseases such as Covid-19 and pneumonia.
But in a trade-off of sorts, this genetic inheritance is also linked to an increase in autoimmune diseases, such as rheumatoid arthritis and inflammatory bowel disease.
To reach this conclusion, the researchers did a study to assess whether variation in the ERAP2 gene was associated with severe infection, autoimmune disease and parental longevity.
The scientists from the United Kingdom’s University of Bristol, in collaboration with colleagues at the universities of Edinburgh, Oxford, Cardiff and Imperial College London, used health data from thousands of UK residents from three large databases (namely, the UK Biobank, FinnGen and GenOMICC).
“This gene essentially chops up proteins for the immune system,” explains study lead author Dr Fergus Hamilton from Bristol, in a news release.
“Although we don’t know the exact mechanism influencing disease risk, carriers of alleles that provide more protection against respiratory disease seem to have an increased risk of autoimmune disease.
“It is potentially a great example of a phenomenon termed ‘balancing selection’, where the same allele has different effects on different diseases.”
“This is a theoretical story of balance – relating to historical and contemporary disease profiles – which reflects our past and is rarely seen in real human examples,” adds study co-author and professor of genetic epidemiology Dr Nicholas Timpson.
Identifying causal links between genetics and disease susceptibility may pave the way for potential treatments, the researchers say.
“However, it also highlights potential challenges; therapeutics to target ERAP2 are currently being developed to target Crohn’s disease and cancer, so it is important to consider potential effects on the risk of infection from these agents,” the news release concludes. – AFP Relaxnews