Variant summary

Our verdict is Likely pathogenic. The variant received 9 ACMG points: 9P and 0B. PM1PM2PM5PP3_ModeratePP5

The NM_003073.5(SMARCB1):c.1130G>A(p.Arg377His) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000125 in 1,593,918 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R377G) has been classified as Likely pathogenic.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 33)

Exomes 𝑓: 6.9e-7 ( 0 hom. )

Consequence

SMARCB1
NM_003073.5 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:2U:1O:1

Conservation

PhyloP100: 9.63

Publications

65 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

SMARCB1 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_pathogenic. The variant received 9 ACMG points.

PM1

In a hotspot region, there are 5 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 13 uncertain in NM_003073.5

PM2

Very rare variant in population databases, with high coverage;

PM5

Other missense variant is known to change same aminoacid residue: Variant chr22-23834151-C-G is described in ClinVar as Likely_pathogenic. ClinVar VariationId is 638627.Status of the report is no_assertion_criteria_provided, 0 stars.

PP3

MetaRNN computational evidence supports a deleterious effect, 0.873

PP5

Variant 22-23834152-G-A is Pathogenic according to our data. Variant chr22-23834152-G-A is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 30203.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_003073.5. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein
SMARCB1	NM_003073.5	MANE Select	c.1130G>A	p.Arg377His	missense	Exon 9 of 9	NP_003064.2
SMARCB1	NM_001362877.2		c.1184G>A	p.Arg395His	missense	Exon 9 of 9	NP_001349806.1
SMARCB1	NM_001317946.2		c.1157G>A	p.Arg386His	missense	Exon 9 of 9	NP_001304875.1

Ensembl Transcripts

Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein
SMARCB1	ENST00000644036.2	MANE Select	c.1130G>A	p.Arg377His	missense	Exon 9 of 9	ENSP00000494049.2
SMARCB1	ENST00000407422.8	TSL:1	c.1103G>A	p.Arg368His	missense	Exon 9 of 9	ENSP00000383984.3
SMARCB1	ENST00000263121.12	TSL:1	c.992G>A	p.Arg331His	missense	Exon 8 of 8	ENSP00000263121.8

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152244

Hom.:

Cov.:

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:

0.00

AC:

AN:

216632

AF XY:

0.00

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

6.94e-7

AC:

AN:

1441674

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

715478

show subpopulations

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

African (AFR)

AF:

0.00

AC:

AN:

32812

American (AMR)

AF:

0.00

AC:

AN:

42852

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

25694

East Asian (EAS)

AF:

0.00

AC:

AN:

38362

South Asian (SAS)

AF:

0.00

AC:

AN:

82836

European-Finnish (FIN)

AF:

0.00

AC:

AN:

51218

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5746

European-Non Finnish (NFE)

AF:

9.07e-7

AC:

AN:

1102618

Other (OTH)

AF:

0.00

AC:

AN:

59536

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.225

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<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:

AN:

152244

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

74374

show subpopulations

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5.

African (AFR)

AF:

0.00

AC:

AN:

41462

American (AMR)

AF:

0.00

AC:

AN:

15292

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3472

East Asian (EAS)

AF:

0.00

AC:

AN:

5196

South Asian (SAS)

AF:

0.00

AC:

AN:

4834

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10628

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.0000147

AC:

AN:

68042

Other (OTH)

AF:

0.00

AC:

AN:

2090

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5. (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.225

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Alfa

AF:

0.0000785

Hom.:

ClinVar

ClinVar submissions as Germline

Significance:Conflicting classifications of pathogenicity

Revision:criteria provided, conflicting classifications

View on ClinVar

rs387906812

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Variant Effect in Transcripts

RefSeq Transcripts

Ensembl Transcripts

Frequencies

Age Distribution

ClinVar

ClinVar submissions as Germline

Computational scores

Publications

Other links and lift over