19-11003113-G-T

Variant summary

Our verdict is Uncertain significance. Variant got 5 ACMG points: 5P and 0B. PM2 PP2 PP3_Moderate

The NM_001387283.1(SMARCA4):c.1897G>T(p.Ala633Ser) variant causes a missense 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 Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. A633I) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 32)
• Consequence: SMARCA4 NM_001387283.1 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 10.0

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 Uncertain_significance. Variant got 5 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant where missense usually causes diseases, SMARCA4
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.875

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
SMARCA4	NM_001387283.1	c.1897G>T	p.Ala633Ser	missense_variant	12/36	ENST00000646693.2
SMARCA4	NM_003072.5	c.1897G>T	p.Ala633Ser	missense_variant	12/35	ENST00000344626.10

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
SMARCA4	ENST00000646693.2	c.1897G>T	p.Ala633Ser	missense_variant	12/36		NM_001387283.1
SMARCA4	ENST00000344626.10	c.1897G>T	p.Ala633Ser	missense_variant	12/35	1	NM_003072.5	P4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 33

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

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Apr 12, 2017

In summary, this variant is a novel missense change with uncertain impact on protein function. It has been classified as a Variant of Uncertain Significance. Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be disruptive, but these predictions have not been confirmed by published functional studies. This variant is not present in population databases (ExAC no frequency) and has not been reported in the literature in individuals with a SMARCA4-related disease. This sequence change replaces alanine with serine at codon 633 of the SMARCA4 protein (p.Ala633Ser). The alanine residue is highly conserved and there is a moderate physicochemical difference between alanine and serine. -

Hereditary cancer-predisposing syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Oct 13, 2020

The p.A633S variant (also known as c.1897G>T), located in coding exon 11 of the SMARCA4 gene, results from a G to T substitution at nucleotide position 1897. The alanine at codon 633 is replaced by serine, an amino acid with similar properties. This amino acid position is highly conserved in available vertebrate species. In addition, the in silico prediction for this alteration is inconclusive. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.64
BayesDel_addAF	Pathogenic	0.18	D
BayesDel_noAF	Uncertain	0.030
Cadd	Uncertain	25
Dann	Uncertain	1.0
DEOGEN2	Benign	0.40	T;.;T;.;.;.;.;.;.;.;T;.;.;.;.;.;T;T;.;.;.;.
Eigen	Pathogenic	0.86
Eigen_PC	Pathogenic	0.80
FATHMM_MKL	Pathogenic	1.0	D
M_CAP	Pathogenic	0.32	D
MetaRNN	Pathogenic	0.87	D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D
MetaSVM	Uncertain	0.18	D
MutationAssessor	Uncertain	2.7	M;.;.;.;M;M;.;M;M;M;M;M;M;M;M;M;.;.;.;.;.;.
MutationTaster	Benign	1.0	D;D;D;D;D;D;D;D;D
PrimateAI	Uncertain	0.69	T
PROVEAN	Uncertain	-2.4	N;.;.;.;.;.;.;.;.;.;N;.;N;.;N;.;.;N;.;.;.;.
REVEL	Uncertain	0.57
Sift	Uncertain	0.025	D;.;.;.;.;.;.;.;.;.;D;.;D;.;D;.;.;D;.;.;.;.
Sift4G	Uncertain	0.039	D;.;.;.;.;.;.;.;.;.;D;.;D;D;D;D;D;D;.;.;.;.
Polyphen		1.0	D;.;D;.;.;.;.;.;.;.;D;.;.;.;.;.;.;D;.;.;.;.
Vest4		0.68
MutPred		0.71		Loss of sheet (P = 0.0181);Loss of sheet (P = 0.0181);Loss of sheet (P = 0.0181);Loss of sheet (P = 0.0181);Loss of sheet (P = 0.0181);Loss of sheet (P = 0.0181);Loss of sheet (P = 0.0181);Loss of sheet (P = 0.0181);Loss of sheet (P = 0.0181);Loss of sheet (P = 0.0181);Loss of sheet (P = 0.0181);Loss of sheet (P = 0.0181);Loss of sheet (P = 0.0181);Loss of sheet (P = 0.0181);Loss of sheet (P = 0.0181);Loss of sheet (P = 0.0181);.;Loss of sheet (P = 0.0181);.;.;.;.;
MVP		0.79
MPC		2.4
ClinPred		0.97	D
GERP RS		4.6
RBP_binding_hub_radar		1.1
RBP_regulation_power_radar		2.8
Varity_R		0.27
gMVP		0.69

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: rs1555768376; hg19: chr19-11113789;