rs964459864

chr19-11060138-G-Achr19-11060138-G-Cchr19-11060138-G-T

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 3P and 1B. PM2 PP2 BP4

The NM_001387283.1(SMARCA4):c.4958G>A(p.Arg1653Gln) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000258 in 1,550,918 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 Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R1653G) has been classified as Uncertain significance.

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 33)
  • Exomes 𝑓: 0.0000021 (0 hom.)
• Consequence: SMARCA4 NM_001387283.1 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:3
• Conservation: PhyloP100: 3.19

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 2 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=0.28444344).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
SMARCA4	NM_001387283.1	c.4958G>A	p.Arg1653Gln	missense_variant	35/36	ENST00000646693.2
SMARCA4	NM_003072.5	c.4862G>A	p.Arg1621Gln	missense_variant	34/35	ENST00000344626.10

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
SMARCA4	ENST00000646693.2	c.4958G>A	p.Arg1653Gln	missense_variant	35/36		NM_001387283.1
SMARCA4	ENST00000344626.10	c.4862G>A	p.Arg1621Gln	missense_variant	34/35	1	NM_003072.5	P4

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152264 Hom.: 0 Cov.: 33

Gnomad AFR AF: 0.0000241

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.00

GnomAD4 exome AF: 0.00000214 AC: 3 AN: 1398654 Hom.: 0 Cov.: 33 AF XY: 0.00000290 AC XY: 2 AN XY: 689878

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: 0.00000278

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152264 Hom.: 0 Cov.: 33 AF XY: 0.0000134 AC XY: 1 AN XY: 74384

Gnomad4 AFR AF: 0.0000241

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.00

Gnomad4 OTH AF: 0.00

Bravo AF: 0.00000756

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Intellectual disability, autosomal dominant 16 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Genome-Nilou Lab

Jul 15, 2021

- -

Rhabdoid tumor predisposition syndrome 2 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Feb 16, 2023

This sequence change replaces arginine, which is basic and polar, with glutamine, which is neutral and polar, at codon 1653 of the SMARCA4 protein (p.Arg1653Gln). The frequency data for this variant in the population databases is considered unreliable, as metrics indicate poor data quality at this position in the gnomAD database. 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: 571088). 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

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Oct 17, 2023

The p.R1653Q variant (also known as c.4958G>A), located in coding exon 34 of the SMARCA4 gene, results from a G to A substitution at nucleotide position 4958. The arginine at codon 1653 is replaced by glutamine, an amino acid with highly 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	Uncertain	0.36
BayesDel_addAF	Uncertain	0.049	T
BayesDel_noAF	Benign	-0.17
Cadd	Pathogenic	26
Dann	Uncertain	1.0
DEOGEN2	Benign	0.28	T;.;T;.;.;.;.;.;.;.;T;.;.;.;.;.;T;T;.;.;.;.
Eigen	Benign	0.056
Eigen_PC	Benign	0.13
FATHMM_MKL	Uncertain	0.95	D
M_CAP	Uncertain	0.16	D
MetaRNN	Benign	0.28	T;T;T;T;T;T;T;T;T;T;T;T;T;T;T;T;T;T;T;T;T;T
MetaSVM	Uncertain	-0.26	T
MutationAssessor	Benign	0.29	N;.;.;.;.;.;.;.;.;.;N;.;.;.;.;.;.;.;.;.;.;.
MutationTaster	Benign	0.88	D;D;D;D;D;D;D;D;D
PrimateAI	Uncertain	0.70	T
PROVEAN	Benign	-0.89	N;.;.;.;.;.;.;.;.;.;N;.;.;.;N;.;.;.;.;.;.;.
REVEL	Uncertain	0.35
Sift	Uncertain	0.016	D;.;.;.;.;.;.;.;.;.;D;.;.;.;D;.;.;.;.;.;.;.
Sift4G	Benign	0.10	T;.;.;.;.;.;.;.;.;.;T;.;T;T;T;T;T;T;.;.;.;.
Polyphen		0.91	P;.;B;.;.;.;.;.;.;.;P;.;.;.;.;.;.;B;.;.;.;.
Vest4		0.24
MVP		0.75
MPC		1.4
ClinPred		0.63	D
GERP RS		3.5
Varity_R		0.16
gMVP		0.58

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: rs964459864; hg19: chr19-11170814;