OGG1 and spina bifida: Olshan et al. conducted a case–control analysis from 250 NTDs (including 125 spina bifida, 125 oral clefts) and 350 non-malformation controls to investigate the relationship between DNA repair gene polymorphisms and NTDs; the results show that the polymorphism of BER gene APE1 (Asp148Glu) reduced the risk of spina bifida, while, on the other hand, the BER genes XRCC1 (Arg399Gln) and OGG1 (Ser326Cys) could increase the risk of spina bifida [10].