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Genetic polymorphism of MTHFR C677 T may modulate the incidence and severity of COVID-19

COVID-19 spreading across world correlates with C677T allele of the methylenetetrahydrofolate reductase (MTHFR) gene prevalence


Background: Homocysteine assessment has been proposed as a potential predictive biomarker for the severity of COVID-19 infection. The purpose of this review was to analyze the correlation between the prevalence of MTHFR C677 T gene polymorphism and COVID-19 incidence and mortality worldwide.

Methods: Data regarding MTHFR C677 T gene mutation were obtained from the interrogation of the Genome Aggregation Database (genomAD), which is publicly available from the web"https://gnomad.broadinstitute.org." COVID-19 cases, including prevalence and mortality, were obtained from"https://www.worldometers.info/coronavirus" 27 August 2020.

Results: There is a clear trend toward the worldwide prevalence of MTHFR 677 T and COVID-19 incidence and mortality. The prevalence of MTHFR 677 T allele in the Latino population, and the incidence and mortality for COVID-19 was higher for this ethnic group than that reported for most other populations globally. Statistical analysis showed a relatively strong correlation between C677 T and death from coronavirus.

Conclusions: Genetic polymorphism of MTHFR C677 T may modulate the incidence and severity of COVID-19 pandemic infection.

Rufous McKinney

Senior Member
Is it necessary to be homozygous for C677?

admitting the genetics things confuse me (I was considering getting my PhD in genetics, back in the day)

So this C677-T ...I"m heterozygous AG at that allele...

And my grandaughter is half Latino so now Im worried about her....and their immediate family has had some bad reaction to COVID and thrombosis is common there....


Senior Member
The full paper is here.

But after a quick read I could not see where the actual increased risk of death for those who have the MTHFR C677T (rs1801133) mutation is given in this paper.

I am +/+ for MTHFR C677T, so I am personally interested.

Those who want to check their MTHFR C677T mutations on 23andme, go HERE.

Note that 23andMe always report on the positive strand, so if you see AA on 23andme, that means you have the double mutation, as that is the same as TT on the negative strand.

The study says that the high homocysteine that this mutation causes may be responsible for the increased risk of death. They say that taking folic acid and B vitamins may help counter the effects of this mutation.

Active folate like folinic acid or methylfolate may be better.

Other homocysteine lowering supplements include vitamin B12 as methylcobalamin and betaine.