A chromatin variant (also known as an epigenetic lesion, epimutation or epigenetic alteration) corresponds to a section of the genome that differs in chromatin states across cell types/states within an individual (intra-individual) or between individuals for a given cell type/state (inter-individual). Chromatin variants distinguish DNA sequences that differ in their function in one cell type/state versus another. Chromatin variants are found across the genome, inclusive of repetitive and non-repetitive DNA sequences.[1] Chromatin variants range in sizes. The smallest chromatin variants cover a few hundred DNA base pairs, such as seen at promoters, enhancers or insulators.[2][3][4][5][6] The largest chromatin variants capture a few thousand DNA base pairs, such as seen at Large Organized Chromatin Lysine domains (LOCKs)[7][8][9][10] and Clusters Of Cis-Regulatory Elements (COREs), such as super-enhancer.[11][12]
References
^Grillo, Giacomo; Lupien, Mathieu (June 2022). "Cancer-associated chromatin variants uncover the oncogenic role of transposable elements". Current Opinion in Genetics & Development. 74 101911. doi:10.1016/j.gde.2022.101911. ISSN1879-0380. PMID35487182.
^Heintzman ND, Stuart RK, Hon G, Fu Y, Ching CW, Hawkins RD, et al. (March 2007). "Distinct and predictive chromatin signatures of transcriptional promoters and enhancers in the human genome". Nature Genetics. 39 (3): 311–8. doi:10.1038/ng1966. PMID17277777. S2CID1595885.
