SMARCB1
protein-codingSWI/SNF related, matrix associated, actin dependent regulator of chromatin, subfamily b, member 1, the group of Protein phosphatase 1 regulatory subunits|BAF complex|PBAF complex
Gene summary
The protein encoded by this gene is part of a complex that relieves repressive chromatin structures, allowing the transcriptional machinery to access its targets more effectively. The encoded nuclear protein may also bind to and enhance the DNA joining activity of HIV-1 integrase. This gene has been found to be a tumor suppressor, and mutations in it have been associated with malignant rhabdoid tumors. Alternatively spliced transcript variants have been found for this gene. [provided by RefSeq, Dec 2015]
- SNF5L1
MANE transcript
Inheritance
ClinVar variants
Top phenotype
gnomAD constraint
Max pathogenic AF
Genomic locus
External References & Databases
Transcript & Mutation Effects
hg38 • Region Span ~51.1 kbGenCC Phenotypes & Disease Associations
Curated gene-disease validity assertions and inheritance patterns
Inheritance Pattern: AD
Disease ID:MONDO:0016995
Submitter: Orphanet
Inheritance Pattern: AD
Disease ID:MONDO:0024517
Submitter: G2P
Inheritance Pattern: AD
Disease ID:MONDO:0015452
Submitter: ClinGen
*SMARCB1* was first reported in relation to autosomal dominant Coffin-Siris syndrome (CSS) in 2012 (PMID: 22426308). Coffin-Siris syndrome is characterized by intellectual disability, coarse facial features, hypertrichosis, sparse scalp hair, and hypoplastic or absent fifth fingernails or toenails. Five missense variants and inframe deletions, including recurrent p.(Lys364del) and p.(Arg37His), reported in 20 probands in 6 publications (PMIDs: 22426308, 23815551, 23906836, 23929686, 25168959, 29907796) are included in this curation. More evidence is available in the literature, but the maximum score for genetic evidence (12 points) has been reached. The mechanism for disease is dominant-negative (PMID: 31759698). This gene-disease relationship is also supported by animal and cell culture models (PMIDs: 31273213, 31759698). Mice with heterozygous disruption of *Smarcb1* exhibit brain midline abnormalities like those seen in CSS individuals (PMID: 31273213). In human induced pluripotent stem cells genetically modified to harbor the recurrent inframe variant p.(Lys364del), neuron count and neurite outgrwoth are diminished, and gene expression is downregulated (PMID: 31759698). In summary, there is definitive evidence to support the relationship between *SMARCB1* and autosomal dominant Coffin-Siris syndrome. This has been repeatedly demonstrated in both the research and clinical diagnostic settings and has been upheld over time. This classification was approved by the ClinGen Intellectual Disability and Autism Gene Curation Expert Panel on August 15, 2023 (SOP Version 9).
Inheritance Pattern: AD
Disease ID:MONDO:0012252
Submitter: Genomics England PanelApp
Inheritance Pattern: AD
Disease ID:MONDO:0013820
Submitter: PanelApp Australia
Inheritance Pattern: AD
Disease ID:MONDO:0012252
Submitter: ClinGen
There is abundant published evidence associating the SMARCB1 gene with rhabdoid tumor predisposition syndrome 1 (RTPS) since the gene-disease relationship was first proposed by Sevenet et al. (1999). Multiple case level studies have been performed with RTPS patients that have variants in the SMARCB1 gene. SMARCA4, another subunit of the SWI/SNF chromatin remodeling complexes, also cause RTPS. SMARCB1 was absent from neoplastic cells of all tested AT/RTs of RTPS patients in immunohistochemical analysis. Multiple Smarcb1 haploinsufficiency mice models indicate the development of malignant rhabdoid tumors in mice. All of these types of evidence are consistent with a definitive relationship between the SMARCB1 gene and rhabdoid tumor predisposition syndrome 1 (RTPS).
Inheritance Pattern: AD
Disease ID:MONDO:0100038
Submitter: Ambry Genetics
Inheritance Pattern: AD
Disease ID:MONDO:0024517
Submitter: Ambry Genetics
Inheritance Pattern: AD
Disease ID:MONDO:0013820
Submitter: G2P
Inheritance Pattern: AD
Disease ID:MONDO:0008075
Submitter: Orphanet
Inheritance Pattern: AD
Disease ID:MONDO:0016473
Submitter: Orphanet
Inheritance Pattern: AD
Disease ID:MONDO:0015452
Submitter: Orphanet
Inheritance Pattern: AD
Disease ID:MONDO:0012252
Submitter: Ambry Genetics
Inheritance Pattern: AD
Disease ID:MONDO:0012252
Submitter: Labcorp Genetics (formerly Invitae)
Inheritance Pattern: AD
Disease ID:MONDO:0013820
Submitter: Labcorp Genetics (formerly Invitae)
Inheritance Pattern: AD
Disease ID:MONDO:0012252
Submitter: G2P
Inheritance Pattern: AD
Disease ID:MONDO:0013820
Submitter: Ambry Genetics
Clinical Genomic Database (CGD)
Manifestation: Cardiovascular; Dermatologic; Musculoskeletal; Neurologic; Oncologic; Genitourinary
Intervention: Oncologic
Rationale: Surveillance/early treatment of tumors may reduce morbidity
ClinVar Associated Diseases & Phenotypes
Reported disease conditions connected to SMARCB1 variants in ClinVar
ClinVar Variants & Pathogenicity by Type
Statistics based on transcript NM_003073.5. 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 | 6 | 336 | 1 | 343 | ||
| missense | 3 | 29 | 501 | 16 | 549 | |
| nonsense | 20 | 4 | 2 | 26 | ||
| start loss | 4 | 1 | 5 | |||
| frameshift | 38 | 11 | 7 | 56 | ||
| splice donor/acceptor (+/-2bp) | 7 | 18 | 6 | 31 | ||
| Total | 68 | 62 | 526 | 353 | 1 | 1010 |
Highest pathogenic variant AF is 0.0000082112365
Transcript Catalog
Annotated transcript isoforms across RefSeq and Ensembl databases
| Transcript ID | Source | Protein ID | Coding Exons | MANE Status |
|---|---|---|---|---|
| RefSeq | NP_003064.2 | 9 | MANE Select | |
| Ensembl | ENSP00000494049.2 | 9 | MANE Select | |
| RefSeq | NP_001007469.1 | 9 | Standard | |
| RefSeq | NP_001304875.1 | 9 | Standard |
Gene Ontology (GO) Annotations & Pathways
Biological processes, molecular functions, cellular components and pathways
Pathways ConsensusPathDB
- Thermogenesis - Homo sapiens (human)
- Hepatocellular carcinoma - Homo sapiens (human)
- Tumor suppressor activity of SMARCB1
- Gene expression (Transcription)
- RUNX1 interacts with co-factors whose precise effect on RUNX1 targets is not known
Biological Process
- RNA polymerase I preinitiation complex assembly
- nucleosome disassembly
- chromatin remodeling
- regulation of transcription by RNA polymerase II
- cell cycle
Molecular Function
- RNA polymerase II proximal promoter sequence-specific DNA binding
- RNA polymerase II distal enhancer sequence-specific DNA binding
- RNA polymerase I CORE element sequence-specific DNA binding
- p53 binding
- DNA binding
Cellular Component
- nuclear chromatin
- fibrillar center
- nucleus
- nucleoplasm
- nucleolus
gnomAD Constraint
Source:
- Gene type
- protein_coding
- Transcript type
- protein_coding
- Transcript
- ENST00000263121
- Coding exons
- 9
- Length
- 47554
- Individuals with no LoFs
- 125742
- Homozygous LoFs
- 0
- Heterozygous LoFs
- 3
- Defined
- 125745
- p
- 0.0000119
| Z-Score | Observed | Expected | Observed/Expected | Mutation Rate | Total Possible | |
|---|---|---|---|---|---|---|
| Missense | 3.60 | 74 | 227 | 0.327 | 0.0000145 | 2537 |
| Missense (PolyPhen) | 20 | 67.578 | 0.29595 | 718 | ||
| Synonymous | -0.346 | 99 | 94.7 | 1.05 | 0.00000691 | 729 |
| Loss of Function | 4.10 | 1 | 21.6 | 0.0464 | 0.00000131 | 234 |
Population LoF Frequency
| Population | CAF | p-value | Status |
|---|---|---|---|
| African | 0 | 0.0 | absent |
| Latino/Admixed American | 0.000029 | 0.000029 | rare |
| Ashkenazi Jewish | 0.000099 | 0.000099 | rare |
| East Asian | 0 | 0.0 | absent |
| Finnish | 0 | 0.0 | absent |
| European (Non-Finnish) | 0.0000088 | 0.0000088 | rare |
| South Asian | 0 | 0.0 | absent |
| Other | 0 | 0.0 | absent |
dbNSFP Gene Annotations
Source:
- Function
- FUNCTION: Core component of the BAF (hSWI/SNF) complex. This ATP- dependent chromatin-remodeling complex plays important roles in cell proliferation and differentiation, in cellular antiviral activities and inhibition of tumor formation. The BAF complex is able to create a stable, altered form of chromatin that constrains fewer negative supercoils than normal. This change in supercoiling would be due to the conversion of up to one-half of the nucleosomes on polynucleosomal arrays into asymmetric structures, termed altosomes, each composed of 2 histones octamers. Stimulates in vitro the remodeling activity of SMARCA4/BRG1/BAF190A. Involved in activation of CSF1 promoter. Belongs to the neural progenitors- specific chromatin remodeling complex (npBAF complex) and the neuron-specific chromatin remodeling complex (nBAF complex). During neural development a switch from a stem/progenitor to a postmitotic chromatin remodeling mechanism occurs as neurons exit the cell cycle and become committed to their adult state. The transition from proliferating neural stem/progenitor cells to postmitotic neurons requires a switch in subunit composition of the npBAF and nBAF complexes. As neural progenitors exit mitosis and differentiate into neurons, npBAF complexes which contain ACTL6A/BAF53A and PHF10/BAF45A, are exchanged for homologous alternative ACTL6B/BAF53B and DPF1/BAF45B or DPF3/BAF45C subunits in neuron-specific complexes (nBAF). The npBAF complex is essential for the self-renewal/proliferative capacity of the multipotent neural stem cells. The nBAF complex along with CREST plays a role regulating the activity of genes essential for dendrite growth (By similarity). Plays a key role in cell-cycle control and causes cell cycle arrest in G0/G1. {ECO:0000250|UniProtKB:Q9Z0H3, ECO:0000269|PubMed:10078207, ECO:0000269|PubMed:12226744, ECO:0000269|PubMed:14604992, ECO:0000269|PubMed:16267391, ECO:0000269|PubMed:16314535, ECO:0000269|PubMed:9448295}.;
- Disease
- DISEASE: Rhabdoid tumor predisposition syndrome 1 (RTPS1) [MIM:609322]: A familial cancer syndrome predisposing to renal or extrarenal malignant rhabdoid tumors and to a variety of tumors of the central nervous system, including choroid plexus carcinoma, medulloblastoma, and central primitive neuroectodermal tumors. Rhabdoid tumors are the most aggressive and lethal malignancies occurring in early childhood. {ECO:0000269|PubMed:9671307, ECO:0000269|PubMed:9892189}. Note=The disease is caused by mutations affecting the gene represented in this entry.; DISEASE: Schwannomatosis 1 (SWNTS1) [MIM:162091]: A cancer syndrome in which patients develop multiple non-vestibular schwannomas, benign neoplasms that arise from Schwann cells of the cranial, peripheral, and autonomic nerves. {ECO:0000269|PubMed:17357086, ECO:0000269|PubMed:18072270}. Note=Disease susceptibility is associated with variations affecting the gene represented in this entry.; DISEASE: Coffin-Siris syndrome 3 (CSS3) [MIM:614608]: A form of Coffin-Siris syndrome, a congenital multiple malformation syndrome with broad phenotypic and genetic variability. Cardinal features are intellectual disability, coarse facial features, hypertrichosis, and hypoplastic or absent fifth digit nails or phalanges. Additional features include malformations of the cardiac, gastrointestinal, genitourinary, and/or central nervous systems. Sucking/feeding difficulties, poor growth, ophthalmologic abnormalities, hearing impairment, and spinal anomalies are common findings. Both autosomal dominant and autosomal recessive inheritance patterns have been reported. {ECO:0000269|PubMed:22426308, ECO:0000269|PubMed:22726846, ECO:0000269|PubMed:23906836}. Note=The disease is caused by mutations affecting the gene represented in this entry.;
Recessive Scores
- pRec
- 0.298
Intolerance Scores
- RVIS EVS
- -0.34
- RVIS percentile EVS
- 30.07
Essentials
- Essential (CRISPR)
- E
- Essential (CRISPR2)
- E
- Essential (gene trap)
- E
- Indispensability pred.
- E
- Indispensability score
- 1.00
Gene Damage Prediction
| All | Recessive | Dominant | |
|---|---|---|---|
| Mendelian | Low | Low | Low |
| Primary Immunodeficiency | Medium | Low | Medium |
| Cancer | Low | Low | Low |