In fact, homozygous deleterious mutation and polymorphisms in the SLC22A12 gene was suggested to be related with a high level of UA and gout in a study.[39] Another study elucidated that C677 mutation in methylene tetrahydrofolate reductase gene was a risk factor of hyperuricemia in elderly Korean men.[40] Among different genotypes (GG, GT, and TT), different UA levels were shown.[41] On the other hand, there are also many influential factors for RDW (e.g., measuring technique, age, gender), which should be considered when interpreting the results. This evidence concerns the gene SLC22A12 and gout.