22-23793671-GC-GCC

Variant names:

• chr22-23793671-G-GC
• rs1555876140
• NM_003073.5:c.351dupC

Variant summary

Our verdict is Pathogenic. The variant received 12 ACMG points: 12P and 0B. PVS1 PM2 PP5_Moderate

The NM_003073.5(SMARCB1):​c.351dupC​(p.Thr118HisfsTer52) variant causes a frameshift change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,872 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Pathogenic (★). Synonymous variant affecting the same amino acid position (i.e. T118T) has been classified as Likely benign. Variant results in nonsense mediated mRNA decay.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: SMARCB1 NM_003073.5 frameshift
• Clinical Significance: Pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 7.91
• Publications: 0 publications found

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

ACMG classification

Our verdict: Pathogenic. The variant received 12 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 22-23793671-G-GC is Pathogenic according to our data. Variant chr22-23793671-G-GC is described in ClinVar as Pathogenic. ClinVar VariationId is 493002.Status of the report is criteria_provided_single_submitter, 1 stars.

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

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	SMARCB1	NM_003073.5	MANE Select	c.351dupC	p.Thr118HisfsTer52	frameshift	Exon 3 of 9	NP_003064.2
	SMARCB1	NM_001362877.2		c.351dupC	p.Thr118HisfsTer62	frameshift	Exon 3 of 9	NP_001349806.1
	SMARCB1	NM_001317946.2		c.324dupC	p.Thr109HisfsTer62	frameshift	Exon 3 of 9	NP_001304875.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	SMARCB1	ENST00000644036.2	MANE Select	c.351dupC	p.Thr118HisfsTer52	frameshift	Exon 3 of 9	ENSP00000494049.2
	SMARCB1	ENST00000407422.8	TSL:1	c.324dupC	p.Thr109HisfsTer52	frameshift	Exon 3 of 9	ENSP00000383984.3
	SMARCB1	ENST00000263121.12	TSL:1	c.351dupC	p.Thr118HisfsTer6	frameshift	Exon 3 of 8	ENSP00000263121.8

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461872 Hom.: 0 Cov.: 32 AF XY: 0.00000138 AC XY: 1 AN XY: 727232

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: 39700

South Asian (SAS) AF: 0.00 AC: 0 AN: 86258

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53410

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 8.99e-7 AC: 1 AN: 1112000

Other (OTH) AF: 0.00 AC: 0 AN: 60396

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Pathogenic:1

Feb 19, 2016

Center for Personalized Medicine, Children's Hospital Los Angeles

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
PhyloP100		7.9
Mutation Taster		=0/200	disease causing (ClinVar)

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

Other links and lift over

dbSNP: rs1555876140; hg19: chr22-24135858;