Table 1 Genotyping conditions of the studied genes

MTHFR

(rs1801133)

C677T SNP

FW: 5′-TGA AGG AGA AGG TGT CTG CGG GA-3′

RV: 5′-AGG ACG GTG CGG TGA GAG TG-3′

Initial denaturation at 95 °C for 3 min

35 cycles:

Denaturation at 95 °C for 20 s

Annealing at 59 °C for 20 s

Extension at 72 °C for 20 s

Extension at 72 °C for 5 min

CC:198 bp

TT: 175 and 23

CT: 198, 175 and 23 bp

TYMS

(rs45445694)

5′UTR tandem repeat

FW: 5′-AGG CGC GCG GAA GGG GTC CT -3′

RV: 5′-TCC GAG CCG GCC ACA GGC AT-3′

Initial denaturation at 95 °C for 3 min,

35 cycles:

Denaturation at 95 °C for 30 s

Annealing at 64 °C for 40 s

Extension at 72 °C for 40 s

Finally, extension at 72 °C for 5 min

(2R/2R):113 bp band

(2R/3R):113 bp and 141 bp bands

(3R/3R) 141 bp band

TYMS (rs151264360) of 3′ UTR [1494del6]

Darl (TTAAAG)

Deletion

FW:

5′-TCA CTG AGGGTA TCT GAC AAT GC-3′

RV:

5′-TGC TGT ATT CTG

GTT TGG ATG C-3′

Initial denaturation: at 95 °C for 3 min

35 cycles of:

Denaturation at 94 °C for 20 s

Annealing at 55 °C for 20 s

Extension 72 °C for 20 s

Final extension for 5 min

(+ 6/ + 6): 240 and 160 bp bands

(− 6/ + 6): 394, 240 and 160 bp bands

(− 6/− 6): 394 bp

DNMT3B

Avr ll

C<T SNP

FW:

5′-TGC TGT GAC AGGCAG AGC AG -3′

RV:

5′-GGT AGC CGG GAA

CTC CAC GG-3′ (109)

Initial denaturation: at 95 °C for 3 min

35 cycles of: denaturation at 94 °C for 20 s

Annealing at 55 °C for 20 s

Extension at 72 °C for 20 s

Final extension: at 72 °C for 5 min

Tt:207 and 173 bp

Tc: 380, 207 and 173 bp

Cc:380 bp