Genetic Predisposition: Neanderthal Genes Linked to Severe COVID-19

A new study contributes to the mounting evidence linking an individual's Neanderthal genetic makeup to the severity of COVID-19

As the COVID-19 pandemic swept the globe, it became increasingly clear that the severity of the disease varied widely among individuals. While factors like age were recognized as risk factors, scientists also suspected that genetic predisposition played a role, as family members often exhibited similar disease severity. Now, research¹ from Italy's Bergamo, one of the early epicenters of the pandemic, has unveiled a compelling link between Neanderthal genes and the development of life-threatening forms of COVID-19.

Researchers at Milan's Mario Negri Institute for Pharmacological Research undertook an extensive study involving nearly 10,000 residents of Bergamo. Their goal was to identify genes associated with severe respiratory illness, particularly those inherited from Neanderthals. The study revealed a significant finding: individuals carrying the Neanderthal haplotype were twice as likely to develop severe pneumonia from COVID-19 and three times more likely to require intensive care with ventilator support.

A "haplotype" refers to a set of DNA variants along a single chromosome that tend to be inherited together. While this research provides critical insights into the relationship between Neanderthal genes and COVID-19 severity, it remains unclear whether this specific haplotype is more prevalent in Bergamo or other regions.

In Bergamo, the study found that 33% of individuals with severe COVID-19 carried the Neanderthal haplotype, while it was less common in mild or asymptomatic cases. Neanderthal genes have previously been linked to susceptibility to various diseases, and approximately 2% of European and Asian genomes inherit these genes.

This Italian study adds to the growing body of evidence suggesting that a cluster of Neanderthal genes elevates the risk of severe COVID-19. A study published in the journal Nature² in September 2020 first proposed the link between a genomic segment from Neanderthals and severe COVID-19. It's estimated that around 16% of Europeans and 50% of South Asians carry this genetic segment.

The absence of the Neanderthal haplotype in Africa may contribute to the lower incidence of severe COVID-19 cases in the region, along with other factors like a younger population. This research underscores the complexity of COVID-19's impact on different populations and highlights the role of genetics in shaping disease outcomes. As scientists continue to unravel the mysteries of the virus, understanding genetic predispositions is becoming increasingly vital in managing and preventing severe cases of COVID-19.

1. Breno, M., Noris, M., Rubis, N., Parvanova, A. I., Martinetti, D., Gamba, S., Liguori, L., Mele, C., Piras, R., Orisio, S., Valoti, E., Alberti, M., Diadei, O., Bresin, E., Rigoldi, M., Prandini, S., Gamba, T., Stucchi, N., Carrara, F., … Remuzzi, G. (2023). A GWAS in the pandemic epicenter highlights the severe COVID-19 risk locus introgressed by Neanderthals. IScience, 26(10), 107629. https://doi.org/10.1016/j.isci.2023.107629

2. Zeberg, H., & Pääbo, S. (2020). The major genetic risk factor for severe COVID-19 is inherited from Neanderthals. Nature, 587(7835), 610–612. https://doi.org/10.1038/s41586-020-2818-3