Article 2 Gene Frequency 2 Genetic Predisposition to Disease 2 Humans 2 MTHFR gene Methylenetetrahydrofolate Reductase (NADPH2) 2 gene 2 gene frequency 2 genetic predisposition 2 genetic variability 2 genetics 2 human 2 methylenetetrahydrofolate reductase (NADPH2) 2 prevalence 2 5,10 methylenetetrahydrofolate reductase (FADH2) 1 Aged 1 Alleles 1 Arab 1 Arabs 1 C677T SNP 1 C677T gene 1 C677 T mutation prevalence 1 COVID-19 1 COVID-19 vulnerability 1 Diabetes Mellitus, Type 2 1 Dyslipidemias 1 Ethnic Groups 1 Female 1 Hispanic 1 Homocysteine 1