Table 1.
Main characteristics of MTHFR C677T polymorphism studies included in the meta-analysis
| Case | Control | Genotype (case/control) | Allele (case/control) | HWE | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| First author | Year | Country | Ethnicity | Source of | n | n | CC | CT | TT | C n (%) | T n (%) | (P)## |
| Brandalizeet al. (21) | 2007 | Brazil | White | HB | 110 | 100 | 44/38 | 45/52 | 21/10 | 133(60)/128(64) | 87(40)/72(36) | 0.20 |
| Littleet al. (45)a | 2008 | England | White | PB | 96 | 226 | 46/86 | 42/119 | 8/21 | 134(70)/291(64)# | 58(30)/161(36) | 0.03 |
| Guo et al.(22) | 2009 | China | Asian | HB | 97 | 102 | 26/20 | 49/57 | 22/25 | 101(52)/97(48) | 93(48)/107(52) | 0.22 |
| Wanget al. (35) | 2012 | China | Asian | HB | 89 | 64 | 10/15 | 41/39 | 38/10 | 61(34)/69(54) | 117(66)/59(46) | 0.07 |
| Chornaet al. (25) | 2011 | Ukraine | European | PB | 27 | 50 | 19/34 | 2/2 | 6/14 | 40(74)/70(70) | 14(26)/30(30) | 0.05 |
| Ali et al.(19) | 2009 | India | Asian | PB | 116 | 214 | 78/176 | 37/36 | 1/2 | 193(83)/388(91) | 39(17)/40(9) | 0.92 |
| Bufalinoet al. (36) | 2010 | Brazil | Mixed | HB | 106 | 184 | 49/95 | 50/72 | 7/17 | 148(70)/262(71) | 64(30)/106(29) | 0.53 |
| Gasparet al. (11) | 2004 | Brazil | Mixed | HB | 336 | 644 | 174/327 | 131/269 | 31/48 | 479(71)/923(72) | 193(29)/365(28) | 0.47 |
| Whites | HB | 235 | 474 | 126/235 | 88/202 | 21/37 | 340(72)/672(71)# | 130(28)/276(29)# | 0.48 | |||
| Nonwhites | HB | 77 | 90 | 40/43 | 31/39 | 6/8 | 111(72)/125(69)# | 43(28)/55(31)# | 0.84 | |||
| Unclassified | HB | 24 | 80 | 8/49 | 12/28 | 4/3 | 28(58)/126(79)# | 20(42)/34(21)# | 0.68 | |||
| Gasparet al. (46) | 1999 | Brazil | White | HB | 59 | 90 | 30/37 | 19/40 | 10/13 | 79 (67)/114 (63) | 39 (33)/66 (37) | 0.68 |
| Millset al. (37) | 2008 | Ireland | White | HB | 465 | 1599 | 205/715 | 212/721 | 48/163 | 622(67)/2151(67)# | 308(33)/1047(33)# | 0.34 |
| Mostowskaet al. (47) | 2006 | Poland | European | PB | 121 | 81 | 60/42* | 46/33* | 15/6* | 166(69)/117(72) | 76 (31)/45 (28) | 0.89 |
| Pezzettiet al. (34) | 2004 | Italy | White | HB | 104 | 289 | 27/95 | 47/151 | 30/43 | 101(49)/341(59) | 107(51)/237(41) | 0.17 |
| Shotelersuket al. (33) | 2003 | Thailand | Asian | PB | 67 | 202 | 46/154 | 19/46 | 2/2 | 111(83)/354(88) | 23(17)/50(12) | 0.48 |
| Sozenet al. (23) | 2009 | Venezuela | Mixed | PB | 168 | 138 | 109/66 | 49/65 | 10/7 | 267(79)/197(71) | 69(21)/79(29) | 0.07 |
| Van Rooijet al. (7) | 2003 | Netherlands | White | PB | 148 | 170 | 78/84 | 55/74 | 15/12 | 211(71)/242(71)# | 85(28)/98(29)# | 0.43 |
| Tolarovaet al. (48) | 1998 | Argentina | White | PB | 93 | 84 | 39/39 | 37/33 | 17/12 | 115(62)/111(66)# | 71(38)/57(34)# | 0.26 |
PB; Population based, HB; Hospital based, HWE; Hardye Weinberg equilibrium, NA; Not available, a; Not enter final analysis because not fit HWE, *; Numbers calculated by text describe, #; Numbers calculated by the distribution of genotype and ##; P value of HWE were calculated by original data.