To the Editor: Mutations in more than 200 genes are known to cause neural-tube defects in mice; less is known about the genetic cause of neural-tube defects in humans.¹ Kibar and colleagues² hypothesized that human neural-tube defects are caused by mutations in VANGL1 and VANGL2, genes that affect planar cell polarity and cause neural-tube defects in mice. They identified mutations in VANGL1 but not in VANGL2 in humans.² We hypothesized that mutations in VANGL2 are lethal to the fetus, and therefore we sequenced VANGL2 in 163 stillborn or miscarried Han Chinese fetuses with neural-tube defects (Table 1 in the Supplementary Appendix, . . .