MTRR and spina bifida: As in the exome dataset of proband SB1A with the EFNB1 variant (rs772228172), four variants were annotated as homozygous (CUBN, COMT, PTCH1 and TRDMT1) and eight variants as heterozygous (CUBN,MTRR, and VANGL1) in the reported spina bifida-related genes (Table 5).