GSE67377
Promoter methylomes of monochorionic twin placentas reveal intrauterine growth restriction specific methylation profiles
Intrauterine growth restriction (IUGR) is one of the most common adverse pregnancy outcomes with high risk of perinatal morbidity and mortality, and affects up to 7% of pregnancies. Here, seven pairs of placentas were employed for whole genomic promoter DNA methylation profiling and some of the candidate differentially methylated promoters were further validated in additional twelve pairs of samples. Consistent with previous report, our results further indicated that IUGR associated placentas harbored a distinct promoter DNA hypomethylation pattern and the result was further confirmed byultra-performance liquid chromatography/tandem mass spectrometry (UPLC-MS/MS) Overall design: In this study, seven pairs of MC twins that were diagnosed as severely growth-discordant (one twin with IUGR but another one was normal) were enrolled for DNA methylation identification.Promoters are defined as the regions crossing the upstream 2200bp and downstream 500bp of the transcriptional start site. A complete set of 34163 genes located in the 22 autosomes and the XY sex chromosomes were prepared based on the RefSeq gene files (http://genome.ucsc.edu/, hg19). The promoters overlapped with each other were merged to form a large region, resulting in 20882 merged candidate regions ranging from 2700bp to 8864bp. The capture probes were designed and synthesized by Roche Nimblegen Incorporation, consisted of 150,407 oligonucleotides.