Comparative analysis of chorionic methylation abnormalities in various pregnancy pathologies

The development of normal pregnancy at early stages is conditioned by epigenetic programs and is impossible without proper formation of the placenta and embryo. In the first trimester, epigenetic mechanisms are involved in these processes, one of which is DNA methylation. DNA methylation is involved in the regulation of various biological processes, such as cell differentiation and development, regulation of gene expression (as a rule, genes with reduced methylation levels in promoters are expressed), X-chromosome inactivation, genome imprinting, maintenance of chromosome stability, and others. Disruption of this process can lead to the formation of pathologic phenotypes such as spontaneous abortion (SA), pre-eclampsia (PE), and gestational diabetes mellitus (GDM). Currently, researchers have found many methylation abnormalities in these pathologies: for example, 54 differentially methylated regions (DMRs) associated with blood pressure, 1703 differentially methylated sites (DMSs) in early-onset pre-eclampsia, more than 200 DMRs in gestational diabetes mellitus, and 4 differentially expressed genes associated with spontaneous abortion have been identified in the trophoblast of chor