- Transcobalamin and methionine synthase reductase mutated polymorphisms aggravate the risk of neural tube defects in humans. Guéant-Rodriguez, R.M., Rendeli, C., Namour, B., Venuti, L., Romano, A., Anello, G., Bosco, P., Debard, R., Gérard, P., Viola, M., Salvaggio, E., Guéant, J.L. Neurosci. Lett. (2003)