en Methylation Status of H19/IGF2 Differentially Methylated Region in in vitro Human Blastocysts Donated by Healthy Couples Medical Biotechnology Medical Biotechnology مقاله کامل Full Length/Original Article <p><strong>Backgrund: </strong>Imprinted genes are a unique subset of few genes, which have been differentially methylated region (DMR) in a parental origin-dependent manner during gametogenesis, and these genes are highly protected during pre-implantation epigenetic reprogramming. Several studies heve shown that the particular vulnerability of imprinting genes during suboptimal pre- and peri-conception microenvironments often occur by assisted reproduction techniques (ART). This study investigated the methylation status of <em>H19/IGF2</em> DMR at high-quality expanding/expanded human blastocysts donated by healthy individuals to evaluate the risks linked to ART. <strong>Method:</strong> Methylation levels of <em>H19</em>/<em>IGF2 </em>DMR were analyzed by bisulfite conversion and sequencing at 18 CpG sites (CpGs) located in this region. <strong>Result:</strong> Results showed that the overall percentage of methylated CpGs and the proportion of hyper-methylated clones of <em>H19/IGF2</em> DMR in analyzed blastocysts were 37.85&plusmn;4.87% and 43.75&plusmn;5.1%, respectively. For validation of our technique, the corresponding methylation levels of peripheral human lymphocytes were defined (49.52&plusmn;1.86% and 50%, respectively). <strong>Conclusion:</strong> Considering the absence of <em>in vivo</em> produced human embryos, it is not possible to conclude that the methylation found in <em>H19</em>/<em>IGF2</em> DMR is actually normal or abnormal. Regarding the possible risks associated with ART, the procedures should be optimized in order to at least reduce some of the epigenetic risks.</p> Blastocyst, Genomic imprinting, H19/IGF2 DMR, Human, Reproductive technique 16 23 http://ibj.pasteur.ac.ir/browse.php?a_code=A-10-1-624&slc_lang=en&sid=1 Marzieh Derakhshan-Horeh No Department of Anatomy, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran Farid Abolhassani abolhasf@sina.tums.ac.ir Yes Department of Anatomy, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran Farnoosh Jafarpour No Department of Reproductive Biotechnology, Reproductive Biomedicine Research Center, Royan Institute for Biotechnology, Academic Center for Education, Culture and Research (ACECR), Isfahan, Iran Ashraf Moini No Department of Endocrinology and Female Infertility, Reproductive Biomedicine Research Centre, Royan Institute for Reproductive Biomedicine, ACECR, Tehran, Iran Khadijeh Karbalaie No Department of Cellular Biotechnology, Cell Science Research Center, Royan Institute for Biotechnology, ACECR, Isfahan, Iran Sayyed Morteza Hosseini No Department of Reproductive Biotechnology, Reproductive Biomedicine Research Center, Royan Institute for Biotechnology, Academic Center for Education, Culture and Research (ACECR), Isfahan, Iran Somayyeh Ostadhosseini No Department of Reproductive Biotechnology, Reproductive Biomedicine Research Center, Royan Institute for Biotechnology, Academic Center for Education, Culture and Research (ACECR), Isfahan, Iran Mohammad Hossein Nasr-Esfahani* mh.nasr-esfahani@royaninstitute.org No Department of Reproductive Biotechnology, Reproductive Biomedicine Research Center, Royan Institute for Biotechnology, Academic Center for Education, Culture and Research (ACECR), Isfahan, Iran