rs587777460

Positions:

• chr19-11030880-G-A
• chr19-11030880-G-C

Variant summary

Our verdict is Pathogenic. Variant got 12 ACMG points: 12P and 0B. PVS1 PM2 PP5_Moderate

The NM_001387283.1(SMARCA4):​c.3533G>A​(p.Trp1178Ter) variant causes a stop gained change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Pathogenic (★). Variant results in nonsense mediated mRNA decay.

• Frequency: Genomes: not found (cov: 32)
• Consequence: SMARCA4 NM_001387283.1 stop_gained
• Clinical Significance: Pathogenic criteria provided, single submitter P:2
• Conservation: PhyloP100: 9.76

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]

ACMG classification

Verdict is Pathogenic. Variant got 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 19-11030880-G-A is Pathogenic according to our data. Variant chr19-11030880-G-A is described in ClinVar as [Pathogenic]. Clinvar id is 139439.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
SMARCA4	NM_001387283.1	c.3533G>A	p.Trp1178Ter	stop_gained	25/36	ENST00000646693.2	NP_001374212.1
SMARCA4	NM_003072.5	c.3533G>A	p.Trp1178Ter	stop_gained	25/35	ENST00000344626.10	NP_003063.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
SMARCA4	ENST00000646693.2	c.3533G>A	p.Trp1178Ter	stop_gained	25/36		NM_001387283.1	ENSP00000495368
SMARCA4	ENST00000344626.10	c.3533G>A	p.Trp1178Ter	stop_gained	25/35	1	NM_003072.5	ENSP00000343896	P4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:2

Revision: criteria provided, single submitter

Submissions by phenotype

Rhabdoid tumor predisposition syndrome 2 Pathogenic:1

Pathogenic, no assertion criteria provided

literature only

OMIM

Sep 01, 2013

- -

Hereditary cancer-predisposing syndrome Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Ambry Genetics

Aug 08, 2023

The p.W1178* pathogenic mutation (also known as c.3533G>A), located in coding exon 24 of the SMARCA4 gene, results from a G to A substitution at nucleotide position 3533. This changes the amino acid from a tryptophan to a stop codon within coding exon 24. This alteration has been reported in the germline of a mother and daughter who were both initially diagnosed with histopathologically similar immature teratomas, which were later reclassified as malignant rhabdoid tumors. Additionally, tumor tissue from both the mother and daughter revealed an additional unique somatic truncating mutation in SMARCA4. This alteration was also absent from the mother's parents, suggesting it occurred de novo in the mother (Poremba C et al. Diagn. Mol. Pathol., 1993 Jun;2:131-6; Witkowski L et al. J. Pathol., 2013 Sep;231:35-43). This alteration is expected to result in loss of function by premature protein truncation or nonsense-mediated mRNA decay. Loss-of-function variants in SMARCA4 are known to cause rhabdoid tumor predisposition syndrome including small cell carcinoma of the ovary-hypercalcemic type (SCCOHT); however, such associations with neurodevelopmental disorders are exceedingly rare (Kosho T et al. Am J Med Genet C Semin Med Genet. 2014 Sep;166C(3):262-75; Jelinic P et al. Nat Genet. 2014 May;46(5):424-6). Based on the supporting evidence, this alteration is pathogenic for rhabdoid tumor predisposition syndrome; however, the association of this alteration with Coffin-Siris syndrome is unlikely. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Pathogenic	0.65
CADD	Pathogenic	51
DANN	Uncertain	1.0
Eigen	Pathogenic	0.94
Eigen_PC	Pathogenic	0.81
FATHMM_MKL	Pathogenic	0.99	D
MutationTaster	Benign	1.0	A;A;A;A;A;A;A;A;A
Vest4		0.99
GERP RS		4.6
RBP_binding_hub_radar		1.1
RBP_regulation_power_radar		2.8

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

LitVar

Other links and lift over

dbSNP: rs587777460; hg19: chr19-11141556; COSMIC: COSV60810149; COSMIC: COSV60810149;