VANGL1 and neural tube defect: While mutations have been observed along the entire span of the VANGL1/2 genes in human NTD patients, mutations known to be causative for NTD in the mouse all map to the C-terminal tail (Chen et al., 2013; El-Hassan et al., 2018; Guyot et al., 2011; Kibar et al., 2001; Murdoch et al., 2001).