Alzheimer’s Gene associated with Severe COVID-19
The gene variant – APOE ε4 that places people at a greater risk of developing Alzheimers disease additionally has been associated with COVID-19 disease. The study is released in The Journals of Gerontology, Series A, on May 26, 2020. The 2 copies of the variant – APOE4, make individuals twice more likely to develop the severe form of COVID-19 caused by SARS-CoV-2, as per the study.
David Melzer and his colleagues, Exeter University used genetic and health data to take a look at the role of the APOE4 variant, which influences cholesterol transport and inflammation on volunteers in the UK Biobank. More than 9,000 out of 383,000 people of European descent included in the study carried 2 copies of the gene variant. The scientists cross-referenced this listing with individuals who tested positive for COVID-19 between March 16 to April 26 – the presumption being that a lot of such cases were serious due to the fact that testing at the time was greatly limited to hospitals. The study suggested that compared to people who had two copies of ε3 – another variant, the APOE4 homozygous genotype was linked to a doubled risk of severe COVID-19.
The outcome isn’t because of nursing home setups or to a better likelihood of having a medical diagnosis of dementia, which none of the 37 people with two copies of APOE4 who tested positive for COVID-19 had in them. Melzer said, “The connection is still there – even if we remove associated disease”. “So obviously it is the gene variant that is playing the role”.
David Curtis, Honorary professor, the University College London Genetics Institute, said “It is still possible that dementia itself is playing a role”. Several of those 37 individuals that tested positive for COVID-19 have or will certainly develop cognitive issues, however, they just don’t have a medical diagnosis presently. “This study does not actually convince me that the ApoE e4 allele is really an independent threat factor for severe COVID-19 condition. I would certainly wish to see this examined in a sample where dementia could be a lot more confidently omitted, perhaps a younger companion. I am sure, to illuminate this issue certain additional information will quickly arise”.
If APOE4 is affecting the course of a COVID-19, it wouldn’t be the very first gene to be pointed as a crucial element. In prior studies, alleles in the ACE2 gene that codes for the protein on host cells that SARS-CoV-2 binds to, in the HLA genes, and in the genes coding the ABO blood types have additionally been associated to severity or susceptibility of COVID-19.
“It is feasible that the role of ApoE in the immune system is very important in the disease and also future study may have the ability to harness this to establish reliable treatments,” said Tara Spires-Jones, neurodegeneration researcher, the University of Edinburgh (did not participate in the study).
Author: Sruthi S