Department of Genetics, Faculty of Medicine, University of Porto, Portugal.
Epigenetics. 2010 Jul 1;5(5):444-50. doi: 10.4161/epi.5.5.12118.
Genomic imprinting is defined as an epigenetic modification that leads to parent-of-origin specific monoallelic expression. Some current research on the fetal control growth has been focused on the study of genes that display imprinted expression in utero. Four imprinted genes, two paternally expressed (IGF2 and PEG10) and two maternally expressed (PHLDA2 and CDKN1C), are well known to play a role in fetal growth and placental development. Pregnancy loss in the general reproductive population is a very common occurrence and other genetic causes beyond chromosomal abnormalities could be involved in spontaneous miscarriages or fetal deaths, such as alteration of expression in imprinted genes particularly those related to fetal or placental growth. Quantitative Real Time PCR was performed to evaluate gene expressions patterns of the four mentioned genes in spontaneous miscarriages or fetal deaths from 38 women. Expression levels of PHLDA2 gene were upregulated in the first trimester pregnancy cases and all four imprinted genes studied were upregulated in the second trimester of pregnancy cases comparing with controls. In third trimester PEG10 was downregulated in fetal samples group. This is the first study presenting data from human imprinted genes expression in spontaneous miscarriages or fetal deaths cases from the three trimesters of pregnancy.
基因组印迹是一种表观遗传修饰，导致亲本来源特异性单等位基因表达。目前对胎儿控制生长的一些研究集中在研究在子宫内表现印迹表达的基因上。四个印迹基因，两个父系表达（IGF2 和 PEG10）和两个母系表达（PHLDA2 和 CDKN1C），已知在胎儿生长和胎盘发育中发挥作用。在普通生殖人群中，妊娠丢失是非常常见的，除了染色体异常之外，其他遗传原因也可能与自然流产或胎儿死亡有关，例如印迹基因表达的改变，特别是与胎儿或胎盘生长相关的基因。进行了定量实时 PCR 以评估 38 名女性自发性流产或胎儿死亡中四个所述基因的基因表达模式。在早孕期病例中，PHLDA2 基因的表达水平上调，与对照组相比，所有研究的四个印迹基因在妊娠中期病例中均上调。在第三个三个月，胎儿样本组中的 PEG10 下调。这是首次在妊娠三个三个月的自发性流产或胎儿死亡病例中呈现人类印迹基因表达数据的研究。
