Table 2 Distribution of MTHFR alleles and genotypes among CHD cases and their parents.
| Cases | Mothers | Fathers | ||||
|---|---|---|---|---|---|---|
| 677C→T | (n = 347) | (n = 341) | (n = 290) | |||
| 677C | 480 (69.2%) | 470 (68.9%) | 403 (69.5%) | |||
| 677T | 214 (30.8%) | 212 (31.1%) | 177 (30.5%) | |||
| 677CC | 169 (48.7%) | 169 (49.6%) | 136 (46.9%) | |||
| 677CT | 142 (40.9%) | 132 (38.7%) | 131 (45.2%) | |||
| 677TT | 36 (10.4%) | 40 (11.7%) | 23 (7.9%) | |||
| 677CT/677TT | 178 (51.3%) | 172 (50.4%) | 154 (53.1%) | |||
| 677CC/677CT | 311 (89.6%) | 301 (88.3%) | 267 (92.1%) | |||
| 1298A→C | (n = 343) | (n = 335) | (n = 276) | |||
| 1298A | 523 (76.2%) | 486 (72.5%) | 394 (71.4%) | |||
| 1298C | 163 (23.8%) | 184 (27.5%) | 158 (28.6%) | |||
| 1298AA | 203 (59.2%) | 177 (52.8%) | 146 (52.9%) | |||
| 1298AC | 117 (34.1%) | 132 (39.4%) | 102 (37.0%) | |||
| 1298CC | 23 (6.7%) | 26 (7.8%) | 28 (10.1%) | |||
| 1298AC/1298CC | 140 (40.8%) | 158 (47.2%) | 130 (47.1%) | |||
| 1298AA/1298AC | 320 (93.3%) | 309 (92.2%) | 248 (89.9%) |
CHD, congenital heart defect; MTHFR, methylenetetrahydrofolate reductase.