Table 2. Distribution of genotypes and allele frequencies of 677C>T MTHFR gene observed in this study compared with those found in other populations. *Statistically significant.
| Sample size (n) | Distribution of 677C>T MTHFR genotype (n) | HWE | Frequency of 677C>T MTHFR alleles | |||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Study | Country | CC | CT | TT | P | T, n (%) | 95% CI | χ2 | P | |
| Present study | 164 | 67 | 87 | 10 | 0.008* | 107 (32.62) | ||||
| Biseli et al, 2008 (6) | Brazil | 194 | 100 | 77 | 17 | 0.69 | 111 (28.61) | -2.941% - 10.98% | 1.167 | P = 0.2800 |
| Boduroglu et al, 2004 (7) | Turkey | 91 | 58 | 30 | 3 | 0.71 | 36 (19.78) | 4.58% - 20.542% | 8.939 | P = 0.0028* |
| Balta et al, 2003 (8) | Turkey | 185 | 90 | 87 | 8 | 0.02* | 103 (27.84) | -2.233% - 11.789% | 1.668 | P = 0.1965 |
| Basol et al, 2016 (9) | Turkey | 126 | 86 | 35 | 5 | 0.55 | 45 (17.86) | 7.442% - 21.779% | 15.300 | P = 0.0001* |
| Thirumaran et al, 2005 (10) | Germany | 1448 | 600 | 681 | 167 | 0.21 | 1015 (35.05) | -3.211% - 7.78% | 0.663 | P = 0.4154 |
| Kurzwelly, 2010 (11) | Germany | 212 | 96 | 96 | 20 | 0.57 | 136 (32.08) | -6.341% - 7.494% | 0.00615 | P = 0.9375 |
| Lightfoot et al, 2005 (12) | UK | 755 | 356 | 316 | 83 | 0.31 | 482 (31.92) | -4.898% - 6.557% | 0.0327 | P = 0.8564 |
| Chango et al, 2005 (13) | France | 119 | 49 | 58 | 12 | 0.39 | 82 (34.45) | -6.234% - 9.991% | 0.134 | P = 0.7148 |
| Coppede et al, 2009 (14) | Italy | 113 | 40 | 55 | 18 | 0.90 | 91 (40.26) | -0.75% - 16.036% | 3.076 | P = 0.0794 |
| Kokotas et al, 2009 (15) | Denmark | 1084 | 545 | 449 | 90 | 0.85 | 629 (29.01) | -1.806% - 9.304% | 1.616 | P = 0.2036 |
| Martinez-Friaz, 2008 (16) | Spain | 188 | 76 | 85 | 27 | 0.68 | 139 (36.97) | -2.912% - 11.526% | 1.273 | P = 0.2592 |
| Meguid et al, 2008 (17) | Egypt | 48 | 33 | 12 | 3 | 0.21 | 18 (18.75) | 3.328% - 22.884% | 6.221 | P = 0.0126* |
| O’Leary et al, 2002 (18) | Ireland | 192 | 90 | 84 | 18 | 0.80 | 120 (31.25) | -5.664% - 8.442% | 0.0963 | P = 0.7563 |
| Wang et al, 2008 (19) | China | 70 | 36 | 29 | 5 | 0.79 | 39 (27.86) | -4.871% - 13.771% | 0.826 | P = 0.3635 |
| Muthuswamy et al, 2016 (20) | India | 110 | 80 | 30 | 0 | 0.09 | 30 (13.64) | 11.693% - 25.821% | 24.297 | P < 0.0001* |
| Jusić-Karić et al, 2016 (3) | BiH | 207 | 91 | 92 | 24 | 0.92 | 140 (33.82) | -5.834% - 8.153% | 0.0708 | P = 0.7902 |
| Mahmutbegović et al, 2017 (4) | BiH | 154 | 71 | 74 | 9 | 0.07 | 92 (29.87) | -4.679% - 10.124% | 0.438 | P = 0.5080 |
| Damnjanovic et al, 2010 (21) | Serbia | 412 | 163 | 190 | 59 | 0.76 | 308 (37.38) | -1.547% - 10.849% | 2.105 | P = 0.1469 |
| Alfirevic et al. 2010 (22) | Croatia | 104 | 37 | 59 | 8 | 0.02* | 75 (36.06) | -5.008% - 12.013% | 0.527 | P = 0.4679 |
| Petra et al, 2007 (23) | Slovenia | 258 | 112 | 110 | 36 | 0.29 | 182 (35.27) | -4.118% - 9.278% | 0.513 | P = 0.4737 |
| Li et al, 2013 (24) | USA | 564 | 236 | 246 | 82 | 0.17 | 410 (36.35) | -2.329% - 9.544% | 1.385 | P = 0.2392 |
| Lincz et al, 2003 (25) | Australia | 299 | 145 | 133 | 21 | 0.19 | 175 (29.26) | -2.975% - 9.833% | 0.976 | P = 0.3232 |