Lin and August performed a meta-analysis on genetic thrombophilias and preeclampsia assessing the relationship between the factor V Leiden (1691 G-A) SNP, the methylene tetrahydrofolate reductase (MTHFR) 677 C-T SNP, and the prothrombin 20210 G-A SNP in all case-control studies with data on these polymorphisms [68]. Here, MTHFR is linked to thrombophilia.