MAT1A and neural tube defect: Pdgfra‐null mice are embryonic lethal with severe NTDs and PDGFRA promoter haplotypes have been associated with NTD susceptibility in humans.34, 35 A stop‐gain variant c.360C>A (p.Cys120Ter) was detected in the methionine adenosyltransferase 1A (MAT1A) gene (Figure 2B).