Table 3.
Studies from 19 countries showing relationship between methylenetetrahydrofolate reductase gene polymorphisms and neural tube defects among subjects of different ethnicities
| Study | Study type | Population type/ethnicity | Subjects | Presence/absence of association or MTHFR polymorphism as a risk factor for NTH |
|---|---|---|---|---|
| Hayati et al., 2008 | Case-control | Malay | 22 cases, 20 controls | No association |
| Sadewa et al., 2002 | Case-control | Indonesian Javanese | 68 cases, 244 controls | No risk factor |
| Dutta et al., 2017 | Case-control | North East Indian | 40 cases, 80 controls | Possible risk factor |
| Boduroglu et al., 1999 | Case-control | Turkish | 91 cases, 93 controls | No association |
| Erdogan, 2010 | Case-control | Turkish | 33 children, 46 controls | No association, no risk factor |
| Behunova et al., 2010 | Case-control | Slovak | 93 cases, 290 controls | No association |
| Barber et al., 2000 | Case-control | American Hispanic | 149 cases, 195 controls | No risk factor |
| Mornet et al., 1997 | Case-control | French | 43 cases, 133 controls | No risk factor |
| Munoz et al., 2007 | Case-control | Mexican | 118 cases, 112 controls | Possible risk factor |
| Nasri et al., 2019 | Case-control | Tunisian | 119 cases, 127 controls | Risk factor in father group |
| Richter et al., 2001 | Case-control | German | 356 cases, 233 controls | No association |
| Nauman et al., 2018 | Case-control | Pakistani | 109 cases, 100 controls | Maternal TT homozygous genotype an independent risk factor |
| Kondo et al., 2014 | Case-control | Japanese | 115 mothers, 4517 controls | No association |
| Kirke et al., 2004 | Case-control | Irish | 397 cases, 848 controls | CT and TT genotype as possible risk factor |
| Naushad et al., 2010 | Case-control | South India | 100 cases, 160 controls | No association, T allele as possible risk factor |
| Cunha et al., 2002 | Case-control | Brazil | 46 cases, 75 controls | No association, no risk factor |
| Yu et al., 2014 | Case-control | Chinese | 271 cases, 192 controls | Some degree of association, risk factor |
| Deb et al., 2001 | Case-control | North India | 111 cases, 220 controls | TT genotype as risk factor depending on religion and nutritional habits |
| Rama Devi et al., 2004 | Cross-sectional | South India | 608 subjects | Strong association |
| Maternal TT genotype as risk factor | ||||
| Pardo et al., 2014 | Cross-sectional | Chile | 105 subjects | No risk factor |
| Green et al., 2013 | Cross-sectional | Irish | 331 subjects | No association |
| Mutchinick et al., 1999 | Cross-sectional | Maxican | 250 subjects | Marked association as well as risk factor |
| Nishio et al., 2008 | Cross-sectional | Japanese | 170 subjects | Marked association |
MTHFR – Methylenetetrahydrofolate reductase; NTD – Neural tube defect