Genetic Factors Influencing COVID-19 Severity

Genetic variation among individuals significantly shapes susceptibility to SARS-CoV-2 infection and progression to severe disease. Early large-scale investigations revealed multiple loci associated with viral entry, immune signalling and inflammatory response. Variants impacting the angiotensin-converting enzyme 2 receptor modulate viral attachment and cell entry. Differences in interferon pathways, notably type I interferon responses, underpin variable antiviral defence, while polymorphisms in genes regulating monocyte–macrophage activation and endothelial integrity influence inflammatory cascades and vascular complications. Alternative splicing in key loci alters isoform diversity, affecting tissue-specific antiviral function in the lung. Rare loss-of-function alleles in innate immune receptors confer heightened risk in young patients, while protective haplotypes inherited from archaic hominins offer moderate resistance in wider populations. An integrated model emerges in which failure to control viral replication or an excessive inflammatory and coagulopathic response predisposes to critical illness. Understanding these mechanisms not only illuminates disease biology but also identifies potential therapeutic and prognostic targets across diverse populations.

Research from Nature Portfolio

Genome-wide association analyses of over 24,000 critically ill COVID-19 patients identified 49 significant loci, including novel signals in genes related to inflammatory signalling (JAK1), monocyte–macrophage activation (PDE4A) and host factors for viral entry (TMPRSS2). Integrative transcriptome-wide association and Mendelian randomisation pinpointed druggable targets across immune and endothelial pathways. Complementary whole-genome sequencing in nearly 7,500 critically ill individuals revealed 23 independent variants, implicating interferon signalling genes (IL10RB, PLSCR1), leukocyte differentiation (BCL11A) and secretor status (FUT2), with evidence for causal roles of cell adhesion molecules and coagulation factors. These findings support a dual-mechanism model of disease susceptibility: impaired viral control and heightened pulmonary inflammation. Additionally, analyses of lung isoform diversity demonstrated that alternative splicing of OAS1, ATP11A, DPP9 and NPNT, rather than overall expression levels, is causally linked to severity. Splicing of MUC1 and PMF1 also modulates susceptibility, offering lung-specific targets for therapeutic development.

Genetic Factors Influencing COVID-19 Severity publication trend

The graph below shows the total number of articles in genetic factors influencing covid-19 severity across all publications each year (not limited to Nature Index journals).

Technical terms

Genome-wide association study (GWAS): A method to scan the entire genome for common genetic variants associated with a trait or disease.

Mendelian randomisation: An analytical approach using genetic variants as proxies for modifiable exposures to infer causal relationships.

Alternative splicing: A process by which different combinations of exons are joined to produce multiple RNA isoforms from a single gene, affecting protein function.

Type I interferon: A class of cytokines critical for early antiviral defence by inducing expression of antiviral genes.

Haplotype: A group of genetic variants inherited together, often spanning several genes or regulatory regions.

References

1. GWAS and meta-analysis identifies 49 genetic variants underlying critical COVID-19. Nature (2023).
2. Whole-genome sequencing reveals host factors underlying critical COVID-19. Nature (2022).
3. Alternative splicing in lung influences COVID-19 severity and respiratory diseases. Nature Communications (2023).
4. Rare predicted loss-of-function variants of type I IFN immunity genes are associated with life-threatening COVID-19. Genome Medicine (2023).
5. Genetic Screening for TLR7 Variants in Young and Previously Healthy Men With Severe COVID-19. Frontiers in Immunology (2021).
6. A genomic region associated with protection against severe COVID-19 is inherited from Neandertals. Proceedings of the National Academy of Sciences of the United States of America (2021).
7. Genome-wide analysis provides genetic evidence that ACE2 influences COVID-19 risk and yields risk scores associated with severe disease. Nature Genetics (2022).
8. Mapping the human genetic architecture of COVID-19. Nature (2021).