差异甲基化区（英语：Differentially methylated regions，DMRs）指在多种样本（组织、细胞、个体等）中基因组里甲基化状态不相同的区域，被看作为可能参与基因转录水平调控的功能性区域。在多种组织中鉴定DMRs（T-DMRs）综合考察了人类组织中表观遗传学的差异[1]。癌症与正常样品间的DMRs（C-DMRs）展示出癌症中甲基化缺失情况[2]。众所周知，DNA甲基化与细胞分化及增殖有关[3]，现找到发育阶段（D-DMRs[4]）及重编程阶段（R-DMRs[5]）中存在的许多DMRs。此外还存在着个体内DMRs（Intra-DMRs），这种DMRs在给定的个体中随着年龄的增长而在全局DNA甲基化过程中发生纵向改变[6]。也有个体间DMRs（Inter-DMRs），这种DMRs在不同个体间存在差异甲基化类型[7]。
QDMR（定量差异甲基化区）is a quantitative approach to quantify methylation difference and identify DMRs from genome-wide methylation profiles by adapting Shannon entropy (https://web.archive.org/web/20151023040525/http://bioinfo.hrbmu.edu.cn/qdmr/). The platform-free and species-free nature of QDMR makes it potentially applicable to various methylation data. This approach provides an effective tool for the high-throughput identification of the functional regions involved in epigenetic regulation. QDMR can be used as an effective tool for the quantification of methylation difference and identification of DMRs across multiple samples.[8]
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