Abnormal methylation of PRDM16 and PTPRN2 genes in chorionic villi in miscarriage

Relevance. Abnormal epigenetic regulation of genes responsible for the development of the embryo and placenta is associated with many pregnancy pathologies. Aim. The aim of this work was to analyze the prevalence of abnormal methylation of the PRDM16 and PTPRN2 genes in chorionic villi of spontaneous abortions with normal karyotype and with the most frequent aneuploidies (trisomy 16 and monosomy X). Materials and Methods. The methylation profile was evaluated using targeted bisulfite massive parallel sequencing in chorionic villi of induced abortions (n = 10), spontaneous abortions with normal karyotype (n = 39), trisomy 16 (n = 17) and monosomy X (n = 20) and peripheral blood lymphocytes of healthy volunteers (n = 6). Results and Discussion. In analyzed genes, differential methylation of individual CpG sites was found in chorionic villi of spontaneous abortions. Despite the absence of significant differences between the groups in the average level of methylation in analyzed gene regions, abnormal methylation of the PRDM16 and PTPRN2 genes were detected for 33 % and 5 % of spontaneous abortions, respectively, indicating a high incidence of epigenetic abnormalities in these genes in the chorionic villi of spontaneous abortions. The level of methylation of the PRDM16 gene significantly correlated with the level of methylation of the retrotransposon LINE-1, which indicates the generalized nature of methylation disorders in spontaneous abortions. Finally, the level of methylation of the PTPRN2 gene depended on the age of mothers of spontaneous abortions with monosomy X, which raises the question of the influence of maternal factors on the methylation profile in this group of spontaneous abortions. Conclusion. The results indicate that epigenetic disorders of the PRDM16 gene may be associated with spontaneous termination of pregnancy in the first trimester.