Table 3.
Summary estimates for the prevalence proportion (PP) of MTHFR C677T in various allele/genotype contrasts, the significance level (p value) of heterogeneity test (Q test), and the I2 metric
| Population | FE estimate (95 % CI) | RE estimate (95 % CI) | I2 | p (Q) |
|---|---|---|---|---|
| All | ||||
| T | 26.0 (25.8–26.3), <0.001 | 24.0 (21.7–26.5), <0.001 | 98.74 | <0.001 |
| C | 74.0 (73.7–74.2), <0.001 | 75.9 (73.5–78.3), <0.001 | 98.74 | <0.001 |
| TT | 6.5 (6.3–6.7), <0.001 | 7.7 (6.5–8.9), <0.001 | 96.25 | <0.001 |
| CT | 33.2 (30.8–35.6), <0.001 | 33.2 (30.8–35.6), <0.001 | 96.49 | <0.001 |
| CC | 50.7 (50.3–51.1), <0.001 | 58.9 (55.4–62.4), <0.001 | 98.41 | <0.001 |
| African | ||||
| T | 10.0 (8.4–11.7), <0.001 | 10.3 (3.8–16.8), 0.002 | 92.79 | <0.001 |
| C | 90.0 (88.3–91.6), <0.001 | 89.7 (83.2–96.2), <0.001 | 92.79 | <0.001 |
| TT | 1.3 (0.3–2.4), 0.01 | 2.4 (–0.0–4.8), <0.001 | 69.43 | 0.006 |
| CT | 18.3 (6.5–30.0), 0.002 | 18.3 (6.5–30.0), <0.001 | 89.03 | <0.001 |
| CC | 77.3 (73.7–80.9), <0.001 | 80.3 (65.0–95.5), <0.001 | 93.57 | <0.001 |
| American (North) | ||||
| T | 28.4 (27.6–29.2), <0.001 | 31.2 (25.7–36.7), <0.001 | 97.58 | <0.001 |
| C | 71.6 (70.8–72.4), <0.001 | 68.8 (63.3–74.3), <0.001 | 97.58 | <0.001 |
| TT | 5.3 (4.8–5.9), <0.001 | 11.9 (8.8–14.9), <0.001 | 95.6 | <0.001 |
| CT | 37.5 (33.5–41.4), <0.001 | 37.5 (33.5–41.4), <0.001 | 87.66 | <0.001 |
| CC | 48.7 (47.5–49.9), <0.001 | 49.8 (41.9–57.7), <0.001 | 97.36 | <0.001 |
| American (South) | ||||
| T | 23.0 (21.3–24.6), <0.001 | 27.8 (19.8–35.8), <0.001 | 95.58 | <0.001 |
| C | 77.0 (75.4–78.7), <0.001 | 72.2 (64.2–80.2), <0.001 | 95.58 | <0.001 |
| TT | 3.4 (2.4–4.4), <0.001 | 7.6 (4.5–10.7), <0.001 | 85.2 | <0.001 |
| CT | 37.9 (29.0–46.9), <0.001 | 37.9 (29.0–46.9), <0.001 | 90.83 | <0.001 |
| CC | 55.0 (52.4–57.7), <0.001 | 53.0 (40.9–65.2), <0.001 | 95.14 | <0.001 |
| Asian | ||||
| T | 24.6 (24.3–25.0), <0.001 | 19.7 (16.0–23.4), <0.001 | 99.13 | <0.001 |
| C | 75.4 (75.0–75.7), <0.001 | 80.3 (76.6–84.0), <0.001 | 99.13 | <0.001 |
| TT | 6.8 (6.5–7.1), <0.001 | 5.5 (3.7–7.2), <0.001 | 97.22 | <0.001 |
| CT | 28.6 (24.8–32.4), <0.001 | 28.6 (24.8–32.4), <0.001 | 97.6 | <0.001 |
| CC | 52.3 (51.7–52.8), <0.001 | 65.9 (60.2–71.6), <0.001 | 98.93 | <0.001 |
| Australian | ||||
| T | 16.3 (14.0–18.6), <0.001 | 20.5 (2.6–38.4), 0.02 | 98.1 | <0.001 |
| C | 83.7 (81.4–86.0), <0.001 | 79.5 (61.6–97.4), <0.001 | 98.1 | <0.001 |
| TT | 2.5 (1.1–3.9), <0.001 | 5.9 (–0.5–12.3), 0.071 | 91.12 | <0.001 |
| CT | 28.8 (6.6–51.0), 0.01 | 28.8 (6.6–51.0), 0.01 | 96.53 | <0.001 |
| CC | 67.2 (63.3–71.2), <0.001 | 65.0 (36.6–93.4), <0.001 | 97.82 | <0.001 |
| European | ||||
| T | 33.0 (32.4–33.6), <0.001 | 34.1 (31.9–36.3), <0.001 | 91.08 | <0.001 |
| C | 67.0 (66.4–67.6), <0.001 | 65.9 (63.7–68.1), <0.001 | 91.08 | <0.001 |
| TT | 9.7 (9.2–10.2), <0.001 | 11.6 (9.9–13.3), <0.001 | 87.33 | <0.001 |
| CT | 44.3 (42.7–45.8), <0.001 | 44.3 (42.7–45.8), <0.001 | 57.83 | <0.001 |
| CC | 44.0 (43.1–45.0), <0.001 | 43.6 (40.8–46.3), <0.001 | 87.77 | <0.001 |