Some studies showed that downregulated KCNQ1OT1 in the placenta was related to the selective intrauterine growth restriction of monozygotic twins (Gou et al., 2017), Beckwith-Wiedemann syndrome (BWS), and Silver-Russell syndrome (SRS) (Azzi et al., 2014; Giabicani et al., 2017). This evidence concerns the gene KCNQ1OT1 and Beckwith-Wiedemann syndrome.