19-10984159-C-T

Variant names:

• chr19-10984159-C-T
• rs1339941779
• NM_001387283.1:c.8C>T

Variant summary

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

The NM_003072.5(SMARCA4):​c.8C>T​(p.Thr3Ile) variant causes a missense change. The variant allele was found at a frequency of 0.000000684 in 1,461,432 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. T3N) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: SMARCA4 NM_003072.5 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 6.08
• 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: 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
SMARCA4	NM_001387283.1	c.8C>T	p.Thr3Ile	missense_variant	Exon 2 of 36	ENST00000646693.2	NP_001374212.1
SMARCA4	NM_003072.5	c.8C>T	p.Thr3Ile	missense_variant	Exon 2 of 35	ENST00000344626.10	NP_003063.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
SMARCA4	ENST00000646693.2	c.8C>T	p.Thr3Ile	missense_variant	Exon 2 of 36		NM_001387283.1	ENSP00000495368.1
SMARCA4	ENST00000344626.10	c.8C>T	p.Thr3Ile	missense_variant	Exon 2 of 35	1	NM_003072.5	ENSP00000343896.4
SMARCA4	ENST00000643549.1	c.8C>T	p.Thr3Ile	missense_variant	Exon 2 of 35			ENSP00000493975.1
SMARCA4	ENST00000541122.6	c.8C>T	p.Thr3Ile	missense_variant	Exon 3 of 35	5		ENSP00000445036.2
SMARCA4	ENST00000643296.1	c.8C>T	p.Thr3Ile	missense_variant	Exon 2 of 34			ENSP00000496635.1
SMARCA4	ENST00000644737.1	c.8C>T	p.Thr3Ile	missense_variant	Exon 2 of 34			ENSP00000495548.1
SMARCA4	ENST00000589677.5	c.8C>T	p.Thr3Ile	missense_variant	Exon 3 of 35	5		ENSP00000464778.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD2 exomes AF: 0.00000404 AC: 1 AN: 247758 AF XY: 0.00

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000289

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: 6.84e-7 AC: 1 AN: 1461432 Hom.: 0 Cov.: 33 AF XY: 0.00 AC XY: 0 AN XY: 727036

African (AFR) AF: 0.00 AC: 0 AN: 33480

American (AMR) AF: 0.0000224 AC: 1 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26128

East Asian (EAS) AF: 0.00 AC: 0 AN: 39696

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

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53038

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

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1111952

Other (OTH) AF: 0.00 AC: 0 AN: 60388

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

May 20, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces threonine, which is neutral and polar, with isoleucine, which is neutral and non-polar, at codon 3 of the SMARCA4 protein (p.Thr3Ile). This variant is present in population databases (no rsID available, gnomAD 0.003%). This variant has not been reported in the literature in individuals affected with SMARCA4-related conditions. ClinVar contains an entry for this variant (Variation ID: 1500930). 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) has been performed at Invitae for this missense variant, however the output from this modeling did not meet the statistical confidence thresholds required to predict the impact of this variant on SMARCA4 protein function. 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

Sep 01, 2023

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.T3I variant (also known as c.8C>T), located in coding exon 1 of the SMARCA4 gene, results from a C to T substitution at nucleotide position 8. The threonine at codon 3 is replaced by isoleucine, an amino acid with similar properties. This amino acid position is well conserved in available vertebrate species. In addition, the in silico prediction for this alteration is inconclusive. Missense and in-frame variants in SMARCA4 are known to cause neurodevelopmental disorders; however, such associations with rhabdoid tumor predisposition syndrome including small cell carcinoma of the ovary-hypercalcemic type (SCCOHT) 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, the association of this alteration with Coffin-Siris syndrome is unknown; however, the association of this alteration with rhabdoid tumor predisposition syndrome is unlikely. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.72
BayesDel_addAF	Uncertain	0.095	D
BayesDel_noAF	Uncertain	-0.020
CADD	Uncertain	25
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.42	T;.;T;.;.;.;.;.;.;.;T;.;.;.;.;.;.;T;T
Eigen	Uncertain	0.38
Eigen_PC	Uncertain	0.48
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.96	.;D;.;.;.;.;D;.;.;.;D;D;.;D;D;D;D;D;D
M_CAP	Uncertain	0.28	D
MetaRNN	Uncertain	0.45	T;T;T;T;T;T;T;T;T;T;T;T;T;T;T;T;T;T;T
MetaSVM	Uncertain	0.26	D
MutationAssessor	Benign	1.0	L;.;.;.;L;L;.;L;L;L;L;.;L;L;L;L;L;.;.
PhyloP100		6.1
PrimateAI	Uncertain	0.72	T
PROVEAN	Benign	-2.0	N;.;.;.;.;.;.;.;.;.;N;.;.;N;.;N;.;N;N
REVEL	Uncertain	0.54
Sift	Uncertain	0.0020	D;.;.;.;.;.;.;.;.;.;D;.;.;D;.;D;.;D;D
Sift4G	Uncertain	0.024	D;.;.;.;.;.;.;.;.;.;D;.;.;D;D;D;D;D;D
Polyphen		0.61	P;.;P;.;.;.;.;.;.;.;P;.;.;.;.;.;.;.;P
Vest4		0.52
MutPred		0.24		Loss of phosphorylation at T3 (P = 0.0012);Loss of phosphorylation at T3 (P = 0.0012);Loss of phosphorylation at T3 (P = 0.0012);Loss of phosphorylation at T3 (P = 0.0012);Loss of phosphorylation at T3 (P = 0.0012);Loss of phosphorylation at T3 (P = 0.0012);Loss of phosphorylation at T3 (P = 0.0012);Loss of phosphorylation at T3 (P = 0.0012);Loss of phosphorylation at T3 (P = 0.0012);Loss of phosphorylation at T3 (P = 0.0012);Loss of phosphorylation at T3 (P = 0.0012);Loss of phosphorylation at T3 (P = 0.0012);Loss of phosphorylation at T3 (P = 0.0012);Loss of phosphorylation at T3 (P = 0.0012);Loss of phosphorylation at T3 (P = 0.0012);Loss of phosphorylation at T3 (P = 0.0012);Loss of phosphorylation at T3 (P = 0.0012);Loss of phosphorylation at T3 (P = 0.0012);Loss of phosphorylation at T3 (P = 0.0012);
MVP		0.74
MPC		0.27
ClinPred		0.64	D
GERP RS		5.0
PromoterAI		0.034	Neutral
Varity_R		0.34
gMVP		0.22
Mutation Taster		=32/68	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

Other links and lift over

dbSNP: rs1339941779; hg19: chr19-11094835;