MS4A1

Overview

MS4A1 encodes the CD20 protein, which is the target of rituximab and other therapeutic monoclonal antibodies. MS4A1 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. In relapsed DLBCLs, MS4A1 is sometimes mutated and these mutations have been shown to reduce CD20 expression.¹

Relevance tier by entity

Entity	Tier	Description
DLBCL	1-a	aSHM target and high-confidence DLBCL gene

Mutation incidence in large patient cohorts (GAMBL reanalysis)

Entity	source	frequency (%)
DLBCL	GAMBL genomes	1.53
DLBCL	Schmitz cohort	1.49
DLBCL	Reddy cohort	1.30
DLBCL	Chapuy cohort	0.43

Mutation pattern and selective pressure estimates

Entity	aSHM	Significant selection	dN/dS (missense)	dN/dS (nonsense)
BL	Yes	No	2.434	29.43
DLBCL	Yes	No	0.000	0.00
FL	Yes	No	0.000	0.00

aSHM regions

chr_name	hg19_start	hg19_end	region	regulatory_comment
chr11	60223385	60225310	TSS	active_promoter

View coding variants in ProteinPaint hg19 or hg38

View all variants in GenomePaint hg19 or hg38

## MS4A1 Expression ## References 1. Rushton CK, Arthur SE, Alcaide M, Cheung M, Jiang A, Coyle KM, Cleary KLS, Thomas N, Hilton LK, Michaud N, Daigle S, Davidson J, Bushell K, Yu S, Rys RN, Jain M, Shepherd L, Marra MA, Kuruvilla J, Crump M, Mann K, Assouline S, Connors JM, Steidl C, Cragg MS, Scott DW, Johnson NA, Morin RD. Genetic and evolutionary patterns of treatment resistance in relapsed B-cell lymphoma. Blood Adv. 2020 Jul 14;4(13):2886-2898. doi: 10.1182/bloodadvances.2020001696. PMID: 32589730; PMCID: PMC7362366.