MRTFB

protein-coding

myocardin related transcription factor B, the group of Myocardin family

Gene summary

Enables transcription coactivator activity. Involved in positive regulation of miRNA transcription; positive regulation of striated muscle tissue development; and positive regulation of transcription by RNA polymerase II. Located in nuclear speck. Implicated in syndromic intellectual disability. [provided by Alliance of Genome Resources, Jun 2026]

Previous symbols:

MKL2

MANE transcript

NM_001308142.2

Inheritance

ClinVar variants

P:4U:152B:19

Top phenotype

MRTFB-related disorder

gnomAD constraint

pLI —, LoF o/e 0.07

Max pathogenic AF

—

Genomic locus

chr16:14,071,319-14,266,773

External References & Databases

Ensembl (ENSG00000186260)

Transcript & Mutation Effects

hg38 • Region Span ~195.5 kb

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GenCC Phenotypes & Disease Associations

Curated gene-disease validity assertions and inheritance patterns

neurodevelopmental disorderMODERATE

Inheritance Pattern: AD

Disease ID:MONDO:0700092

Submitter: PanelApp Australia

neurodevelopmental disorderLIMITED

Inheritance Pattern: AD

Disease ID:MONDO:0700092

Submitter: G2P

ClinVar Associated Diseases & Phenotypes

Reported disease conditions connected to MRTFB variants in ClinVar

5 Conditions Cataloged

not specifiedTotal: 152

not providedTotal: 12

MRTFB-related disorderTotal: 8

MRTFB-related neurodevelopmental disorderTotal: 3

MKL2-related disordersTotal: 1

ClinVar Variants & Pathogenicity by Type

Statistics based on transcript NM_001308142.2. 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	1 clinvar		2 clinvar	6 clinvar	2 clinvar	11
missense	2 clinvar	1 clinvar	149 clinvar	9 clinvar	2 clinvar	163
nonsense						0
start loss						0
frameshift						0
splice donor/acceptor (+/-2bp)			1 clinvar			1
Total	3	1	152	15	4	175

Loading ClinVar variants...

Transcript Catalog

Annotated transcript isoforms across RefSeq and Ensembl databases

Showing 4 of 72 transcripts

Transcript ID	Source	Protein ID	Coding Exons	MANE Status
NM_001308142.2	RefSeq	NP_001295071.1	15	MANE Select
ENST00000571589.6	Ensembl	ENSP00000459626.2	15	MANE Select
NM_001365411.2	RefSeq	NP_001352340.1	15	Standard
NM_001365412.2	RefSeq	NP_001352341.1	14	Standard

Gene Ontology (GO) Annotations & Pathways

Biological processes, molecular functions, cellular components and pathways

Biological Process

muscle organ development
positive regulation of striated muscle tissue development
positive regulation of transcription by RNA polymerase II
smooth muscle cell differentiation

Molecular Function

transcription coactivator activity
protein binding
cadherin binding

Cellular Component

nucleus

gnomAD Constraint

Source: gnomAD

Gene type: protein_coding
Transcript type: protein_coding
Transcript: ENST00000318282
Coding exons: 15
Length: 195453
Individuals with no LoFs: 125737
Homozygous LoFs: 0
Heterozygous LoFs: 10
Defined: 125747
p: 0.0000398

	Z-Score	Observed	Expected	Observed/Expected	Mutation Rate	Total Possible
Missense	0.523	548	584	0.939	0.0000316	6848
Missense (PolyPhen)		163	230.59	0.70688		2817
Synonymous	-1.40	260	233	1.12	0.0000138	2145
Loss of Function	5.85	3	45.6	0.0657	0.00000238	527

Population LoF Frequency

Population	CAF	p-value	Status
African	0	0.0	absent
Latino/Admixed American	0	0.0	absent
Ashkenazi Jewish	0	0.0	absent
East Asian	0.000054	0.000054	rare
Finnish	0	0.0	absent
European (Non-Finnish)	0.00011	0.000079	rare
South Asian	0	0.0	absent
Other	0	0.0	absent

dbNSFP Gene Annotations

Source: dbNSFP

Function: FUNCTION: Acts as a transcriptional coactivator of serum response factor (SRF). Required for skeletal myogenic differentiation. {ECO:0000269|PubMed:14565952}.;
Disease: DISEASE: Note=A chromosomal aberration involving C11orf95 is found in 3 chondroid lipomas. Translocation t(11;16)(q13;p13) with C11orf95 produces a C11orf95-MRTFB fusion protein (PubMed:20607705). {ECO:0000269|PubMed:20607705}.;

Recessive Scores

pRec: 0.0835

Intolerance Scores

RVIS EVS: -1.55
RVIS percentile EVS: 3.27