22-23793684-C-T

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 2P and 0B. PM2

The NM_003073.5(SMARCB1):​c.358C>T​(p.Leu120Phe) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000186 in 1,614,048 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★★). Synonymous variant affecting the same amino acid position (i.e. L120L) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)
Exomes 𝑓: 0.0000014 ( 0 hom. )

Consequence

SMARCB1
NM_003073.5 missense

Scores

3
9
7

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:2

Conservation

PhyloP100: 7.91

Publications

1 publications found
Variant links:
Genes affected
SMARCB1 (HGNC:11103): (SWI/SNF related, matrix associated, actin dependent regulator of chromatin, subfamily b, member 1) 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]
SMARCB1 Gene-Disease associations (from GenCC):
  • Coffin-Siris syndrome
    Inheritance: AD Classification: DEFINITIVE, SUPPORTIVE Submitted by: Orphanet, ClinGen
  • intellectual disability, autosomal dominant 15
    Inheritance: AD Classification: DEFINITIVE, STRONG, MODERATE Submitted by: G2P, Ambry Genetics, Labcorp Genetics (formerly Invitae)
  • rhabdoid tumor predisposition syndrome 1
    Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: G2P, Genomics England PanelApp, Ambry Genetics, Labcorp Genetics (formerly Invitae), ClinGen
  • SMARCB1-related schwannomatosis
    Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: G2P, Ambry Genetics
  • familial multiple meningioma
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
  • familial rhabdoid tumor
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
  • schwannomatosis
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
  • complex neurodevelopmental disorder
    Inheritance: AD Classification: LIMITED Submitted by: Ambry Genetics

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 2 ACMG points.

PM2
Very rare variant in population databases, with high coverage;

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
SMARCB1NM_003073.5 linkc.358C>T p.Leu120Phe missense_variant Exon 3 of 9 ENST00000644036.2 NP_003064.2 Q12824-1
SMARCB1NM_001362877.2 linkc.358C>T p.Leu120Phe missense_variant Exon 3 of 9 NP_001349806.1
SMARCB1NM_001317946.2 linkc.331C>T p.Leu111Phe missense_variant Exon 3 of 9 NP_001304875.1 G5E975Q9H836
SMARCB1NM_001007468.3 linkc.331C>T p.Leu111Phe missense_variant Exon 3 of 9 NP_001007469.1 Q12824-2

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
SMARCB1ENST00000644036.2 linkc.358C>T p.Leu120Phe missense_variant Exon 3 of 9 NM_003073.5 ENSP00000494049.2 Q12824-1

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152192
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.0000147
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.00000398
AC:
1
AN:
251484
AF XY:
0.00000736
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.0000544
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000137
AC:
2
AN:
1461856
Hom.:
0
Cov.:
32
AF XY:
0.00000138
AC XY:
1
AN XY:
727234
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33480
American (AMR)
AF:
0.00
AC:
0
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39696
South Asian (SAS)
AF:
0.0000116
AC:
1
AN:
86258
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53412
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
8.99e-7
AC:
1
AN:
1111986
Other (OTH)
AF:
0.00
AC:
0
AN:
60396
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.550
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
GnomAD4 genome
AF:
0.00000657
AC:
1
AN:
152192
Hom.:
0
Cov.:
32
AF XY:
0.00
AC XY:
0
AN XY:
74322
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41456
American (AMR)
AF:
0.00
AC:
0
AN:
15276
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5196
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4828
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10594
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
68048
Other (OTH)
AF:
0.00
AC:
0
AN:
2094
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.525
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
Alfa
AF:
0.00
Hom.:
0
Bravo
AF:
0.00000378
ExAC
AF:
0.00000824
AC:
1

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:2
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not provided Uncertain:1
Mar 13, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces leucine, which is neutral and non-polar, with phenylalanine, which is neutral and non-polar, at codon 120 of the SMARCB1 protein (p.Leu120Phe). This variant is present in population databases (rs754350320, gnomAD 0.006%). This variant has not been reported in the literature in individuals affected with SMARCB1-related conditions. ClinVar contains an entry for this variant (Variation ID: 410712). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is not expected to disrupt SMARCB1 protein function with a negative predictive value of 80%. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Hereditary cancer-predisposing syndrome Uncertain:1
Jan 12, 2023
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The p.L120F variant (also known as c.358C>T), located in coding exon 3 of the SMARCB1 gene, results from a C to T substitution at nucleotide position 358. The leucine at codon 120 is replaced by phenylalanine, an amino acid with highly similar properties. This amino acid position is highly conserved in available vertebrate species. In addition, the in silico prediction for this alteration is inconclusive. Missense and in-frame variants in SMARCB1 are known to cause neurodevelopmental disorders; however, such associations with rhabdoid tumor predisposition syndrome are exceedingly rare (Kosho T et al. Am J Med Genet C Semin Med Genet. 2014 Sep;166C(3):262-75; Eaton KW et al. Pediatr Blood Cancer. 2011 Jan;56(1):7-15). Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.16
BayesDel_addAF
Uncertain
0.098
D
BayesDel_noAF
Uncertain
0.070
CADD
Uncertain
23
DANN
Uncertain
1.0
DEOGEN2
Uncertain
0.44
.;T;T;.;.;T
Eigen
Uncertain
0.59
Eigen_PC
Pathogenic
0.67
FATHMM_MKL
Pathogenic
0.99
D
LIST_S2
Benign
0.52
.;.;.;.;T;D
M_CAP
Uncertain
0.11
D
MetaRNN
Uncertain
0.46
T;T;T;T;T;T
MetaSVM
Uncertain
0.68
D
MutationAssessor
Benign
1.2
.;L;.;.;.;.
PhyloP100
7.9
PrimateAI
Pathogenic
0.82
D
PROVEAN
Benign
-1.2
N;.;N;N;.;N
REVEL
Uncertain
0.48
Sift
Benign
0.065
T;.;T;T;.;T
Sift4G
Benign
0.20
T;.;T;T;.;T
Polyphen
0.56, 0.99, 1.0
.;P;D;.;.;D
Vest4
0.58
MutPred
0.16
Loss of ubiquitination at K115 (P = 0.0896);.;Loss of ubiquitination at K115 (P = 0.0896);.;Loss of ubiquitination at K115 (P = 0.0896);.;
MVP
0.71
MPC
2.0
ClinPred
0.58
D
GERP RS
5.5
Varity_R
0.26
gMVP
0.51
Mutation Taster
=35/65
disease causing

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.0
Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

Other links and lift over

dbSNP: rs754350320; hg19: chr22-24135871; API