Association between COVID-19 and myasthenia gravis (MG): A genetic correlation and Mendelian randomization study

Area of Science:

• Genetics
• Epidemiology
• Neurology

Background:

• Observational studies suggest a link between COVID-19 and myasthenia gravis (MG).
• Investigating genetic correlation and causality is crucial for understanding this potential association.
• Myasthenia gravis is a neuromuscular disorder affecting voluntary muscles.

Purpose of the Study:

• To estimate the genetic correlation between COVID-19 (susceptibility, hospitalization, severity) and myasthenia gravis phenotypes.
• To assess the causal relationship between COVID-19 outcomes and myasthenia gravis using Mendelian randomization.
• To investigate potential genetic links in early- and late-onset myasthenia gravis.

Main Methods:

• Employed linkage disequilibrium score regression (LDSC) to assess genetic correlation.
• Utilized Mendelian randomization (MR) with inverse variance weighted, MR-Egger, and weighted median methods for causal inference.
• Conducted sensitivity analyses using Cochran's Q test, MR-PRESSO, and MR-Egger intercept to ensure result robustness.

Main Results:

• LDSC analysis revealed no significant genetic correlation between COVID-19 susceptibility, hospitalization, severity, and MG phenotypes (p > 0.05).
• MR analysis did not provide evidence for a causal effect of COVID-19 on MG phenotypes (p > 0.05).
• Sensitivity analyses confirmed the robustness and consistency of the null findings.

Conclusions:

• This study found no evidence of genetic correlation or causal relationship between COVID-19 and myasthenia gravis.
• Larger genome-wide association study (GWAS) datasets are required for future investigations into COVID-19 and MG associations.
• Further research is needed to clarify the complex interplay between viral infections and autoimmune neuromuscular disorders.