Table 2.
Genotype and allele frequencies of DNA methyltransferases (DNMTs), methylenetetrahydrofolate reductase (MTHFR), and 5-methyltetrahydrofolate-homocysteine methyltransferase reductase (MTRR) gene polymorphisms in study groups.
| DSCHD+ N (%) |
DSCHD− N (%) |
CHD N (%) |
χ2 DSCHD+ DSCHD− |
p DSCHD+ DSCHD− |
χ2 DSCHD+ CHD |
p DSCHD+ CHD |
||||
|---|---|---|---|---|---|---|---|---|---|---|
| DNMT1 | rs2228611 | Genotype | AA AG GG |
31 (24.0) 80 (62.0) 18 (14.0) |
38 (31.7) 66 (55.0) 16 (13.3) |
27 (29.3) 46 (50.0) 19 (20.7) |
1.81 1.26 0.02 |
0.180 0.262 0.887 |
0.78 3.16 1.73 |
0.377 0.076 0.191 |
| Allele | A G |
142 (55.0) 116 (45.0) |
142 (59.2) 98 (40.8) |
100 (54.3) 84 (45.7) |
0.87 | 0.353 | 0.02 | 0.886 | ||
| DNMT3A | rs1550117 | Genotype | AA AG GG |
1 (0.8) 21 (16.7) 104 (82.5) |
1 (0.8) 17 (14.3) 101 (84.9) |
1 (1.1) 15 (16.5) 75 (82.4) |
0.00 0.27 0.24 |
0.737 0.607 0.622 |
0.05 0.00 0.00 |
0.664 0.972 0.981 |
| Allele | A G |
23 (10.0) 229 (90.0) |
19 (8.0) 219 (92.0) |
17 (9.3) 165 (90.7) |
0.20 | 0.652 | 0.04 | 0.485 | ||
| DNMT3B | rs1569686 | Genotype | GG TG TT |
50 (38.5) 63 (48.5) 17 (13.0) |
45 (36.3) 65 (52.4) 14 (11.3) |
32 (34.8) 38 (41.3) 22 (23.9) |
0.13 0.40 0.19 |
0.721 0.528 0.664 |
0.31 1.11 4.37 |
0.576 0.292 0.039 |
| Allele | G T |
163 (63) 97 (37) |
155 (63) 93 (38) |
102 (55) 82 (45) |
0.00 | 0.964 | 2.36 | 0.125 | ||
| rs2424913 | Genotype | CC CT TT |
41 (33.1) 52 (41.9) 31 (25.0) |
35 (30.2) 66 (56.9) 15 (12.9) |
29 (32.2) 37 (41.1) 24 (26.7) |
0.23 5.37 5.63 |
0.630 0.021 0.019 |
0.02 0.01 0.08 |
0.897 0.904 0.783 |
|
| Allele | C T |
134 (54) 114 (46) |
136 (59) 96 (41) |
95 (53) 85 (47) |
1.03 | 0.311 | 0.07 | 0.246 | ||
| MTHFR | rs1801133 | Genotype | CC CT TT |
51 (38.1) 68 (50.7) 15 (11.2) |
58 (46.7) 55 (44.4) 11 (8.9) |
45 (48.5) 37 (40.2) 10 (10.9) |
2.01 1.06 0.38 |
0.157 0.305 0.537 |
2.64 2.43 0.01 |
0.106 0.120 0.939 |
| Allele | C T |
170 (63.4) 98 (36.6) |
171 (68.9) 77 (31.1) |
127 (69.0) 57 (31.0) |
1.75 | 0.186 | 1.51 | 0.219 | ||
| rs1801131 | Genotype | AA AC CC |
76 (56.7) 55 (41.1) 3 (2.2) |
55 (44.4) 65 (52.4) 4 (3.2) |
41 (44.6) 46 (50.0) 5 (5.4) |
3.94 3.35 0.24 |
0.048 0.068 0.457 |
3.23 1.77 1.63 |
0.073 0.184 0.181 |
|
| Allele | A C |
207 (77.2) 61 (22.8) |
175 (70.6) 73 (29.4) |
128 (69.6) 56 (30.4) |
2.99 | 0.085 | 3.35 | 0.068 | ||
| MTRR | rs1801394 | Genotype | AA AG GG |
32 (24.1) 70 (52.6) 31 (23.3) |
23 (18.5) 72 (58.1) 29 (23.4) |
16 (17.4) 59 (64.1) 17 (18.5) |
1.09 0.77 0.00 |
0.297 0.382 0.988 |
1.44 2.94 0.76 |
0.232 0.087 0.386 |
| Allele | A G |
134 (50.4) 132 (49.6) |
118 (47.6) 130 (52.4) |
91 (49.5) 93 (50.5) |
0.40 | 0.527 | 0.04 | 0.848 | ||
DSCHD+: Down syndrome individuals with congenital heart defects; DSCHD−: Down syndrome individuals without congenital heart defects; CHD: individuals with non-syndromic congenital heart defects; χ2: chi-square test; p: p-value.