Overview

CIITA encodes the major histocompatibility complex (MHC) class II transactivator. CIITA mutations are frequent in PMBCL. These mutations often include structural genomic rearrangements, missense, nonsense, and frameshift mutations. In PMBCL, these mutations are thought to contribute to loss of MHC expression.1 Although loss of CIITA and MHC Class II Expression is commonly observed in DLBCL, the role of mutations and methylation affecting this locus remains unclear.2 CIITA is one of a number of genes affected by aberrant somatic hypermutation in B-cell lymphomas, which complicates the interpretation of mutations at this locus.

Experimental Evidence

Driver mutations affecting this gene in DLBCL have been experimentally demonstrated to cause a reduction or loss of function (LOF).1

Relevance tier by entity

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Mutation incidence in large patient cohorts (GAMBL reanalysis)

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Mutation pattern and selective pressure estimates

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aSHM regions

chr_name hg19_start hg19_end region regulatory_comment
chr16 10970795 10975465 TSS active_promoter-strong_enhancer

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Expression

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References

1.
Mottok A, Woolcock B, Chan FC, Tong KM, Chong L, Farinha P, Telenius A, Chavez E, Ramchandani S, Drake M, Boyle M, Ben-Neriah S, Scott DW, Rimsza LM, Siebert R, Gascoyne RD, Steidl C. Genomic Alterations in CIITA Are Frequent in Primary Mediastinal Large B Cell Lymphoma and Are Associated with Diminished MHC Class II Expression. Cell Rep. 2015 Nov 17;13(7):1418–1431.
2.
Morin RD, Mendez-Lago M, Mungall AJ, Goya R, Mungall KL, Corbett RD, Johnson NA, Severson TM, Chiu R, Field M, Jackman S, Krzywinski M, Scott DW, Trinh DL, Tamura-Wells J, Li S, Firme MR, Rogic S, Griffith M, Chan S, Yakovenko O, Meyer IM, Zhao EY, Smailus D, Moksa M, Chittaranjan S, Rimsza L, Brooks-Wilson A, Spinelli JJ, Ben-Neriah S, Meissner B, Woolcock B, Boyle M, McDonald H, Tam A, Zhao Y, Delaney A, Zeng T, Tse K, Butterfield Y, Birol I, Holt R, Schein J, Horsman DE, Moore R, Jones SJM, Connors JM, Hirst M, Gascoyne RD, Marra MA. Frequent mutation of histone-modifying genes in non-Hodgkin lymphoma. Nature. 2011 Jul 27;476(7360):298–303. PMCID: PMC3210554