Gene variation linked to less severe COVID-19 among South Asian populations
doi:10.1038/nindia.2021.84 Published online 12 June 2021
The novel coronavirus enters human cells by binding to a cell-surface protein known as angiotensin-converting enzyme 2 (ACE2). An international research team now suggests that a specific genetic variant of the ACE2 gene — the gene that codes for this protein — may be the reason for the low case fatality rate among South Asians, including Indian populations1.
Scientists from the Banaras Hindu University in Varanasi and the CSIR-Centre for Cellular and Molecular Biology in Hyderabad, India analysed the frequency of the genetic variations in ACE2 gene in Indian populations and compared them with those of other populations from Asia and Europe.
They found that COVID-19 cases and case fatality rate (CFR) data in India were not associated with rs10490770, the genetic segment linked with disease severity in global data. India's cases and CFR data were also not associated with rs2285666, the genetic segment of ACE2 that modulates the susceptibility of Indians to COVID-19.
Further, the researchers also found no association of the genomic segment rs1049077 with COVID-19 cases or (CFR) in India. This genomic segment, inherited by modern humans from ancestral Neanderthals, is found in 16% people of European descent and in 50% of South Asian descent.
This is striking and suggests a complex susceptibility response among Indian populations, the researchers say. Along with genetic structure, other factors such as socio-economic status and hygiene may have contributed to their susceptibility, they suggest.
These findings, the researchers say, suggest that the genetic risk factor that may be responsible for COVID-19 severity in European populations may not have a significant role in COVID-19 severity in South Asia.
1. Singh, P. P. et al. The major genetic risk factor for severe COVID‑19 does not show any association among South Asian populations. Sci. Rep.11:12346 (2021) doi:10.1038/s41598-021-91711-4