rs765325777

chr19-10984277-G-Achr19-10984277-G-Cchr19-10984277-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.126G>A(p.Met42Ile) variant causes a missense change. The variant allele was found at a frequency of 0.00000657 in 152,222 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 nucleotide change resulting in same amino acid change has been previously reported as Uncertain significancein ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. M42V) has been classified as Uncertain significance.

• Frequency: Genomes: 𝑓 0.0000066 (0 hom., cov: 32)
• Consequence: SMARCA4 NM_001387283.1 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 6.84

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=0.38590503).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
SMARCA4	NM_001387283.1	c.126G>A	p.Met42Ile	missense_variant	2/36	ENST00000646693.2
SMARCA4	NM_003072.5	c.126G>A	p.Met42Ile	missense_variant	2/35	ENST00000344626.10

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
SMARCA4	ENST00000646693.2	c.126G>A	p.Met42Ile	missense_variant	2/36		NM_001387283.1
SMARCA4	ENST00000344626.10	c.126G>A	p.Met42Ile	missense_variant	2/35	1	NM_003072.5	P4

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152222 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.000193

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 Cov.: 33

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152222 Hom.: 0 Cov.: 32 AF XY: 0.0000134 AC XY: 1 AN XY: 74366

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.000193

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.00

Gnomad4 OTH AF: 0.00

Bravo AF: 0.00000378

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

Jan 21, 2024

This sequence change replaces methionine, which is neutral and non-polar, with isoleucine, which is neutral and non-polar, at codon 42 of the SMARCA4 protein (p.Met42Ile). This variant is not present in population databases (gnomAD no frequency). 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: 238369). 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

Sep 26, 2023

The p.M42I variant (also known as c.126G>A), located in coding exon 1 of the SMARCA4 gene, results from a G to A substitution at nucleotide position 126. The methionine at codon 42 is replaced by isoleucine, an amino acid with highly similar properties. This amino acid position is highly 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	0.55
BayesDel_addAF	Uncertain	0.077	D
BayesDel_noAF	Benign	-0.13
Cadd	Uncertain	25
Dann	Uncertain	0.99
DEOGEN2	Uncertain	0.45	T;.;T;.;.;.;.;.;.;.;T;.;.;.;.;.;.;T;T
Eigen	Uncertain	0.28
Eigen_PC	Uncertain	0.34
FATHMM_MKL	Uncertain	0.94	D
M_CAP	Uncertain	0.16	D
MetaRNN	Benign	0.39	T;T;T;T;T;T;T;T;T;T;T;T;T;T;T;T;T;T;T
MetaSVM	Uncertain	0.20	D
MutationAssessor	Benign	1.1	L;.;.;.;L;L;.;L;L;L;L;.;L;L;L;L;L;.;.
MutationTaster	Benign	1.0	D;D;D;D;D;D;D;D;D
PrimateAI	Uncertain	0.78	T
PROVEAN	Benign	-2.0	N;.;.;.;.;.;.;.;.;.;N;.;.;N;.;N;.;N;N
REVEL	Uncertain	0.40
Sift	Uncertain	0.028	D;.;.;.;.;.;.;.;.;.;D;.;.;D;.;D;.;D;D
Sift4G	Uncertain	0.031	D;.;.;.;.;.;.;.;.;.;D;.;.;D;D;D;D;D;D
Polyphen		0.53	P;.;P;.;.;.;.;.;.;.;P;.;.;.;.;.;.;.;P
Vest4		0.29
MutPred		0.20		Gain of glycosylation at S41 (P = 0.0273);Gain of glycosylation at S41 (P = 0.0273);Gain of glycosylation at S41 (P = 0.0273);Gain of glycosylation at S41 (P = 0.0273);Gain of glycosylation at S41 (P = 0.0273);Gain of glycosylation at S41 (P = 0.0273);Gain of glycosylation at S41 (P = 0.0273);Gain of glycosylation at S41 (P = 0.0273);Gain of glycosylation at S41 (P = 0.0273);Gain of glycosylation at S41 (P = 0.0273);Gain of glycosylation at S41 (P = 0.0273);Gain of glycosylation at S41 (P = 0.0273);Gain of glycosylation at S41 (P = 0.0273);Gain of glycosylation at S41 (P = 0.0273);Gain of glycosylation at S41 (P = 0.0273);Gain of glycosylation at S41 (P = 0.0273);Gain of glycosylation at S41 (P = 0.0273);Gain of glycosylation at S41 (P = 0.0273);Gain of glycosylation at S41 (P = 0.0273);
MVP		0.65
MPC		0.28
ClinPred		0.84	D
GERP RS		3.9
Varity_R		0.42
gMVP		0.38

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: rs765325777; hg19: chr19-11094953;