Studies have shown that SHMT1 knockout mice exhibit a significantly increased incidence of neural tube defects (NTDs) when subjected to low-folate and low-choline diets, highlighting SHMT1 as a critical regulator of folate metabolism during neural tube development (Beaudin et al., 2012, Beaudin et al., 2011, Martiniova et al., 2015). The gene discussed is SHMT1; the disease is isolated spina bifida.