The results indicated that the genotype AG of MTHFR rs3737964 (OR = 0.54, 95% CI 0.31–0.97, P = 0.038) and MTHFR rs4846048 (OR = 0.54, 95% CI 0.30–0.98, P = 0.042) were protective factors for HFS, whereas the genotype CT of TYMS rs2853741 (OR = 2.25, 95% CI 1.31–3.87, P = 0.012) was a risk factor for HFS (Table 4). This evidence concerns the gene TYMS and Hand-foot syndrome.