One patient (735F97) was heterozygous for the missense variant c.2852C>A (p.Ser951Tyr) previously reported in a patient with NKH.30 While Mthfr‐null mice do not display a NTD phenotype, Gldc deficient mice variably display NTDs and/or features of NKH.11 We did not identify variants in other GCS genes, AMT or GCSH, after filtering for frequency (<1% MAF) and mutation prediction in our cohort. Here, MTHFR is linked to neural tube defect.