MTHFR and type 2 diabetes mellitus: The MTHFR gene has numerous single nucleotide polymorphisms (SNPs) while two of them, rs1801133 (MTHFR C677T) and rs1801131 (MTHFR A1298C) were extensively investigated concerning the risk of T2DM, although the results were conflicting (Pathak et al., 2022; Shorikov et al., 2022; El Alami et al., 2024).