MZB1

protein-coding

marginal zone B and B1 cell specific protein

Gene summary

Involved in positive regulation of cell population proliferation. Located in cytoplasm and extracellular region. [provided by Alliance of Genome Resources, Jul 2025]

MANE transcript

NM_016459.4

Inheritance

—

ClinVar variants

U:23B:6

Top phenotype

—

gnomAD constraint

pLI —, LoF o/e 0.77

Max pathogenic AF

—

Genomic locus

chr5:139,387,467-139,390,081

External References & Databases

Ensembl (ENSG00000170476)

Transcript & Mutation Effects

hg38 • Region Span ~2.6 kb

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GenCC Phenotypes & Disease Associations

Curated gene-disease validity assertions and inheritance patterns

No GenCC data available for this gene.

ClinVar Associated Diseases & Phenotypes

Reported disease conditions connected to MZB1 variants in ClinVar

2 Conditions Cataloged

not specifiedTotal: 27

not providedTotal: 3

ClinVar Variants & Pathogenicity by Type

Statistics based on transcript NM_016459.4. Only rare variants are included.

We include only reliable ClinVar variants with their consequences to MANE Select, MANE Plus Clinical transcripts, or transcripts with TSL equal to 1. Click a count to filter the variants table below.

Slight differences between displayed counts and ClinVar may occur due to a different transcript/consequence chosen by our variant effect predictor, or because we classify Benign/Likely benign as Likely benign and Pathogenic/Likely pathogenic as Likely pathogenic.

Effect	PathogenicP	Likely pathogenicLP	VUS	Likely benignLB	BenignB	Sum
synonymous				2 clinvar		2
missense			23 clinvar	4 clinvar		27
nonsense						0
start loss						0
frameshift						0
splice donor/acceptor (+/-2bp)						0
Total	0	0	23	6	0	29

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Transcript Catalog

Annotated transcript isoforms across RefSeq and Ensembl databases

Showing 4 of 8 transcripts

Transcript ID	Source	Protein ID	Coding Exons	MANE Status
NM_016459.4	RefSeq	NP_057543.2	4	MANE Select
ENST00000302125.9	Ensembl	ENSP00000303920.8	4	MANE Select
ENST00000417694.6	Ensembl	ENSP00000415420.2	2	Standard
ENST00000503351.1	Ensembl	ENSP00000424481.1	2	Standard

Gene Ontology (GO) Annotations & Pathways

Biological processes, molecular functions, cellular components and pathways

Biological Process

positive regulation of immunoglobulin biosynthetic process
apoptotic process
positive regulation of cell population proliferation
regulation of B cell proliferation
integrin activation

Cellular Component

extracellular region
endoplasmic reticulum lumen
endoplasmic reticulum chaperone complex

gnomAD Constraint

Source: gnomAD

Gene type: protein_coding
Transcript type: protein_coding
Transcript: ENST00000302125
Coding exons: 4
Length: 2602
Individuals with no LoFs: 124470
Homozygous LoFs: 0
Heterozygous LoFs: 14
Defined: 124484
p: 0.0000562

	Z-Score	Observed	Expected	Observed/Expected	Mutation Rate	Total Possible
Missense	0.413	90	102	0.885	0.00000572	1149
Missense (PolyPhen)		32	34.053	0.9397		439
Synonymous	0.346	40	42.9	0.933	0.00000234	396
Loss of Function	0.605	6	7.83	0.767	3.93e-7	87

Population LoF Frequency

Population	CAF	p-value	Status
African	0	0.0	absent
Latino/Admixed American	0.000067	0.000058	rare
Ashkenazi Jewish	0	0.0	absent
East Asian	0.000061	0.000056	rare
Finnish	0.000050	0.000046	rare
European (Non-Finnish)	0.000070	0.000062	rare
South Asian	0.000073	0.000065	rare
Other	0.00018	0.00017	rare

dbNSFP Gene Annotations

Source: dbNSFP

Function: FUNCTION: Associates with immunoglobulin M (IgM) heavy and light chains and promotes IgM assembly and secretion. May exert its effect by acting as a molecular chaperone or as an oxidoreductase as it displays a low level of oxidoreductase activity (By similarity). Isoform 2 may be involved in regulation of apoptosis. Helps to diversify peripheral B-cell functions by regulating Ca(2+) stores, antibody secretion and integrin activation. {ECO:0000250, ECO:0000269|PubMed:11350957, ECO:0000269|PubMed:21688198}.;

Intolerance Scores

RVIS EVS: 0.06
RVIS percentile EVS: 58.53

Essentials

Essential (CRISPR): N
Essential (CRISPR2): N
Essential (gene trap): N

Gene Damage Prediction

	All	Recessive	Dominant
Mendelian	Medium	Medium	Medium
Primary Immunodeficiency	Medium	Medium	Medium
Cancer	Medium	Medium	Medium