en Cancer Cancer Original Article Original Article <p dir="ltr" style="text-align: justify;">Myelodysplastic syndromes (MDSs) are a clonal bone marrow (BM) disease characterized by ineffective hematopoiesis, dysplastic maturation and progression to acute myeloid leukemia (AML). Methylation silencing of <em>HRK </em>has been found in several human malignancies. In this study, we explored the association of <em>HRK</em> methylation status with its expression, clinical parameters and MDS subtypes in MDS patients. To study the methylation status of <em>HRK</em> gene, we applied Methylation Sensitive-High Resolution Melting Curve Analysis (MS-HRM) in MDS patients, as well as healthy controls and EpiTect&reg;PCR Control DNA. Real time RT-PCR was used for gene expression analysis. Methylation frequency in promoter region of <em>HRK </em>in patient samples was 20.37%. Methylation of <em>HRK </em>was significantly related to transcriptional downregulation (P=0.023). The difference in frequency of hypermethylated <em>HRK</em> gene was significant between good (10%) and poor (71.42%) cytogenetic risk groups (P= 0.001), advanced stage MDS patients (66.66%) in comparison with early stage MDS patients (2.56%) (P= 0.00), higher- risk MDS group (61.53%) and lower- risk MDS group (7.31%) (P= 0.00). <em>HRK</em> hypermethylation was associated with advanced- stage MDS and downregulation of <em>HRK</em> gene may play a role in the progression of MDS.</p> High Resolution Melting (HRM), methylation, myelodysplastic syndrome, HRK 90 99 http://ijmcmed.org/browse.php?a_code=A-10-732-1&slc_lang=en&sid=1 Farhad Zaker farhadz20@yahoo.co.uk 10031947532846007359 10031947532846007359 No Cellular and Molecular Research Center, Iran University of Medical Sciences, Tehran, Iran. Naser Amirizadeh amiri_na@yahoo.com 10031947532846007360 10031947532846007360 No Blood transfusion research center, High institute for Education and Research in Transfusion Medicine, Tehran, Iran. Nahid Nasiri nahid.nasiri64@yahoo.com 10031947532846007361 10031947532846007361 Yes Department of Hematology, School of Allied Medicine, Iran University of Medical Sciences, Tehran, Iran. Seyed Mohsen Razavi s_m_raz@yahoo.com 10031947532846007362 10031947532846007362 No Hematology and Oncology Department, Firoozgar Hospital, Iran University of Medical Sciences, Tehran, Iran. Ladan Teimoori-Toolabi lateimoori@gmail.com 10031947532846007363 10031947532846007363 No Molecular Medicine Department, Biotechnology Research Center, Pasteur Institute of Iran, Tehran, Iran. Marjan Yaghmaie marjan_yaghmaie@yahoo.com 10031947532846007364 10031947532846007364 No Hematology, Oncology and Stem cell Transplantation Research Center, Tehran University of Medical Sciences, Tehran, Iran. Roya Mehrasa mehrasa.roya@yahoo.com 10031947532846007365 10031947532846007365 No Blood transfusion research center, High institute for Education and Research in Transfusion Medicine, Tehran, Iran.