TCF7L2 and COVID-19: They may also be associated with a predisposition to comorbidities, as in the cases of SNPs in other genes with higher frequency in this population associated with a worse prognosis of chronic conditions (such as the SNP rs7903146 of the TCF7L2 gene associated with a worse prognosis of type 2 Diabetes Mellitus [DM2] in population from Southern Brazilian Region), which may be more prevalent in this population and influence the worse clinical evolution of COVID-19 (Assmann et al., 2014; Bastos et al., 2021).