H19 and isolated spina bifida: In contrast, when CTCF is bound, this allows H19 to be expressed to produce miR-675, which has been shown to supress growth during gestation and is linked to downregulation of IGF1R. 49 Increased IGF2 DRM0 methylation has also been linked to decreased IGF2 mRNA expression levels.50 In turn, this has been associated with lower birth weight20 and other health problems such as neural tube defects.50