Life-threatening course in coronavirus disease 2019 (COVID-19): Is there a link to methylenetetrahydrofolic acid reductase (MTHFR) polymorphism and hyperhomocysteinemia?

As the current COVID-19 pandemic develops and epidemiological data reveals differences in geographical spread as well as risk factors for developing a severe course of illness, hypotheses regarding possible underlying mechanisms need to be developed and tested. In our hypothesis, we explore the rational for a role of MTHFR polymorphism C677T as a possible explanation for differences in geographical and gender distribution in disease severity. We also discuss the role of the resulting hyper-homocysteinemia, its interaction with the C677T polymorphism and its influence on immune state as well as risk factors for severe disease. Finally, we consider possible dietary ways to influence the underlying pathomechanisms prophylactically and supportively.