19-11039556-G-T

Variant names:

• chr19-11039556-G-T
• rs1555787264
• NM_001387283.1:c.4266+3G>T

Variant summary

Our verdict is Likely benign. The variant received -2 ACMG points: 2P and 4B. PM2 BP4_Strong

The NM_001387283.1(SMARCA4):​c.4266+3G>T variant causes a splice region, intron change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. 3/3 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Uncertain significance (★★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: SMARCA4 NM_001387283.1 splice_region, intron
• Scores: Splicing: ADA: 0.003884
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: -0.312
• Publications: 0 publications found

Genes affected

SMARCA4 (HGNC:11100): (SWI/SNF related, matrix associated, actin dependent regulator of chromatin, subfamily a, member 4) The protein encoded by this gene is a member of the SWI/SNF family of proteins and is similar to the brahma protein of Drosophila. Members of this family have helicase and ATPase activities and are thought to regulate transcription of certain genes by altering the chromatin structure around those genes. The encoded protein is part of the large ATP-dependent chromatin remodeling complex SNF/SWI, which is required for transcriptional activation of genes normally repressed by chromatin. In addition, this protein can bind BRCA1, as well as regulate the expression of the tumorigenic protein CD44. Mutations in this gene cause rhabdoid tumor predisposition syndrome type 2. Multiple transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, May 2012]

SMARCA4 Gene-Disease associations (from GenCC):

• Coffin-Siris syndrome

  Inheritance: AD Classification: DEFINITIVE, SUPPORTIVE Submitted by: ClinGen, Orphanet, Illumina
• intellectual disability, autosomal dominant 16

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: G2P, Labcorp Genetics (formerly Invitae), Ambry Genetics
• rhabdoid tumor predisposition syndrome 2

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Ambry Genetics, ClinGen, Genomics England PanelApp, Labcorp Genetics (formerly Invitae), G2P
• uterine corpus sarcoma

  Inheritance: AR Classification: MODERATE Submitted by: Genomics England PanelApp
• familial rhabdoid tumor

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• hereditary nonpolyposis colon cancer

  Inheritance: AD Classification: LIMITED Submitted by: ClinGen

ACMG classification

Our verdict: Likely_benign. The variant received -2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.68).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
SMARCA4	NM_001387283.1	c.4266+3G>T		splice_region_variant, intron_variant	Intron 30 of 35	ENST00000646693.2	NP_001374212.1
SMARCA4	NM_003072.5	c.4171-1751G>T		intron_variant	Intron 29 of 34	ENST00000344626.10	NP_003063.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
SMARCA4	ENST00000646693.2	c.4266+3G>T		splice_region_variant, intron_variant	Intron 30 of 35		NM_001387283.1	ENSP00000495368.1
SMARCA4	ENST00000344626.10	c.4171-1751G>T		intron_variant	Intron 29 of 34	1	NM_003072.5	ENSP00000343896.4
SMARCA4	ENST00000643549.1	c.4167+3G>T		splice_region_variant, intron_variant	Intron 29 of 34			ENSP00000493975.1
SMARCA4	ENST00000541122.6	c.4072-1742G>T		intron_variant	Intron 29 of 34	5		ENSP00000445036.2
SMARCA4	ENST00000643296.1	c.4072-1742G>T		intron_variant	Intron 28 of 33			ENSP00000496635.1
SMARCA4	ENST00000644737.1	c.4072-1742G>T		intron_variant	Intron 28 of 33			ENSP00000495548.1
SMARCA4	ENST00000589677.5	c.4072-1742G>T		intron_variant	Intron 29 of 34	5		ENSP00000464778.1
SMARCA4	ENST00000643995.1	c.3583-1742G>T		intron_variant	Intron 26 of 31			ENSP00000496004.1
SMARCA4	ENST00000644963.1	c.2815-1742G>T		intron_variant	Intron 22 of 27			ENSP00000495599.1
SMARCA4	ENST00000644065.1	c.2797-1742G>T		intron_variant	Intron 21 of 26			ENSP00000493615.1
SMARCA4	ENST00000642350.1	c.2656-1742G>T		intron_variant	Intron 21 of 26			ENSP00000495355.1
SMARCA4	ENST00000643857.1	c.2524-1742G>T		intron_variant	Intron 20 of 24			ENSP00000494159.1
SMARCA4	ENST00000538456.4	c.328-1742G>T		intron_variant	Intron 3 of 7	3		ENSP00000495197.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 26

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Rhabdoid tumor predisposition syndrome 2 Uncertain:1

Apr 17, 2020

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change falls in intron 30 of the SMARCA4 gene. It does not directly change the encoded amino acid sequence of the SMARCA4 protein, but it affects a nucleotide within the consensus splice site of the intron. This variant is not present in population databases (ExAC no frequency). This variant has not been reported in the literature in individuals with SMARCA4-related conditions. Nucleotide substitutions within the consensus splice site are a relatively common cause of aberrant splicing (PMID: 17576681, 9536098). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site, but this prediction has not been confirmed by published transcriptional studies. 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

May 28, 2024

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.4266+3G>T intronic variant results from a G to T substitution 3 nucleotides after coding exon 29 in the SMARCA4 gene. This nucleotide position is highly conserved in available vertebrate species. In silico splice site analysis predicts that this alteration will not have any significant effect on splicing. Based on the available evidence, the clinical significance of this variant remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.68
CADD	Benign	13
DANN	Benign	0.93
PhyloP100		-0.31
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.0
Mutation Taster		=99/1	polymorphism

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Benign	0.0039
dbscSNV1_RF	Benign	0.31
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: rs1555787264; hg19: chr19-11150232;