December 11, 2020

expert reaction to study looking into genetic mechanisms of critical illness with COVID-19

A study published in Nature looks at genetic variants linked to the development of life-threatening illness in patients with COVID-19.

This Roundup accompanied an SMC Briefing.

Dr David Strain, Clinical Senior Lecturer, University of Exeter and chair of the British Medical Association’s Medical Academic Staff Committee, said:

“This is incredibly interesting paper that elucidates why some people are at a higher risk of a mild infection progressing into a life threatening condition. It is of interest that at least one of the gene SNPs (Single nucleotide polymorphisms – the gene mutation that they are exploring) referred to here is more common in people of Indian and African origin, which is in keeping with the observation that people from these ethnic groups are at higher risk of a poor outcome from COVID-19.

“One major limitation of this study, however, is that they attempted to exclude individuals who had previously tested positive for Coronavirus. Ideally, in order to differentiate between those with susceptibility to severe disease, all the controls would also have been exposed to Coronavirus, and we would be comparing those who tested positive but had only mild disease with those who went on to be hospitalised.

“Currently, the implications for this are limited. These data are useful for predicting those that are at risk, however the majority of us do not know what our genes look like. In the near future, however, the additional interest may arise from a greater understanding what these genes do. A knowledge of what they do may lead to  greater opportunities to develop future treatments. For example, the TYK2 gene is associated with  the inflammatory responses that are known to cause the “cytokine storm” that is responsible for the death of younger patients who contract from this condition. The reason this is of interest is that there are treatments that can block (inhibit) the receptor to this (JAK receptor) and thus may present an therapeutic option going forward (particularly given that the individuals most likely to experience cytokine storm are lower down the priority list for vaccinations).

“The other area of interest is the association between a genetic predictor of adiposity (obesity) and poor outcomes. This suggests that the association may be of genetic origin, therefore lifestyle measures to tackle obesity may not be of benefit it this represents a predisposition rather than an effect of obesity itself. The authors themselves highlight the biases in the populations that they enrolled in the study and their comparators, however this is an important consideration going forward.”

‘Genetic mechanisms of critical illness in Covid-19’ by Erola Pairo-Castineira et al. was published in Nature on Friday 11 December

DOI: https://doi.org/10.1038/s41586-020-03065-y

All our previous output on this subject can be seen at this weblink:

www.sciencemediacentre.org/tag/covid-19

Declared interests

None received.