19-11041530-T-C

Variant summary

Our verdict is Uncertain significance. Variant got 1 ACMG points: 3P and 2B. PM2 PP2 BP4_Moderate

The NM_001387283.1(SMARCA4):c.4490T>C(p.Ile1497Thr) variant causes a missense change. The variant allele was found at a frequency of 0.000000685 in 1,458,846 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Synonymous variant affecting the same amino acid position (i.e. I1497I) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.9e-7 (0 hom.)
• Consequence: SMARCA4 NM_001387283.1 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:4 B:1
• Conservation: PhyloP100: 4.14

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 1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant where missense usually causes diseases, SMARCA4
• BP4: Computational evidence support a benign effect (MetaRNN=0.24666354).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
SMARCA4	NM_001387283.1	c.4490T>C	p.Ile1497Thr	missense_variant	31/36	ENST00000646693.2
SMARCA4	NM_003072.5	c.4394T>C	p.Ile1465Thr	missense_variant	30/35	ENST00000344626.10

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
SMARCA4	ENST00000646693.2	c.4490T>C	p.Ile1497Thr	missense_variant	31/36		NM_001387283.1
SMARCA4	ENST00000344626.10	c.4394T>C	p.Ile1465Thr	missense_variant	30/35	1	NM_003072.5	P4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000401 AC: 1 AN: 249298 Hom.: 0 AF XY: 0.00 AC XY: 0 AN XY: 135076

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000892

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 6.85e-7 AC: 1 AN: 1458846 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 725858

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 9.01e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

Alfa AF: 0.0000621 Hom.: 0

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:4 Benign:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Rhabdoid tumor predisposition syndrome 2 Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	Invitae	Jan 30, 2024	This sequence change replaces isoleucine, which is neutral and non-polar, with threonine, which is neutral and polar, at codon 1497 of the SMARCA4 protein (p.Ile1497Thr). This variant is present in population databases (no rsID available, gnomAD 0.0009%). 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: 480563). 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. -
Uncertain significance, criteria provided, single submitter	clinical testing	Baylor Genetics	May 17, 2023	- -

Intellectual disability, autosomal dominant 16 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Genome-Nilou Lab

Jul 15, 2021

- -

SMARCA4-related disorder Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

PreventionGenetics, part of Exact Sciences

Dec 08, 2022

The SMARCA4 c.4490T>C variant is predicted to result in the amino acid substitution p.Ile1497Thr. To our knowledge, this variant has not been reported in the literature. This variant is reported in 0.00089% of alleles in individuals of European (Non-Finnish) descent in gnomAD (http://gnomad.broadinstitute.org/variant/19-11152206-T-C). At this time, the clinical significance of this variant is uncertain due to the absence of conclusive functional and genetic evidence. -

Hereditary cancer-predisposing syndrome Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Ambry Genetics

Sep 26, 2022

This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.14
BayesDel_addAF	Benign	-0.097	T
BayesDel_noAF	Benign	-0.38
Cadd	Uncertain	25
Dann	Uncertain	0.99
DEOGEN2	Uncertain	0.76	D;.;T;.;.;.;.;.;.;.;D;.;.;.;.;.;T;T;.;.;.;.;.
Eigen	Benign	0.065
Eigen_PC	Benign	0.17
FATHMM_MKL	Uncertain	0.95	D
M_CAP	Benign	0.032	D
MetaRNN	Benign	0.25	T;T;T;T;T;T;T;T;T;T;T;T;T;T;T;T;T;T;T;T;T;T;T
MetaSVM	Benign	-1.0	T
MutationAssessor	Uncertain	2.2	M;.;.;.;.;.;.;.;.;.;M;.;.;.;.;.;.;.;.;.;.;.;.
MutationTaster	Benign	1.0	D;D;D;D;D;D;D;D;D
PrimateAI	Pathogenic	0.89	D
PROVEAN	Uncertain	-3.3	D;.;.;.;.;.;.;.;.;.;D;.;.;.;D;.;.;.;.;.;.;.;.
REVEL	Benign	0.089
Sift	Benign	0.030	D;.;.;.;.;.;.;.;.;.;D;.;.;.;D;.;.;.;.;.;.;.;.
Sift4G	Benign	0.066	T;.;.;.;.;.;.;.;.;.;T;.;T;T;T;T;T;T;.;.;.;.;.
Polyphen		0.025	B;.;D;.;.;.;.;.;.;.;B;.;.;.;.;.;.;D;.;.;.;.;.
Vest4		0.49
MVP		0.36
MPC		1.3
ClinPred		0.85	D
GERP RS		4.4
RBP_binding_hub_radar		0.92
RBP_regulation_power_radar		2.0
Varity_R		0.63
gMVP		0.96

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: rs1377505488; hg19: chr19-11152206;