NM_001387283.1:c.124A>G

Variant names:

• chr19-10984275-A-G
• rs1060502081
• NM_001387283.1:c.124A>G

Variant summary

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

The NM_001387283.1(SMARCA4):​c.124A>G​(p.Met42Val) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000206 in 1,458,838 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. M42I) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000021 (0 hom.)
• Consequence: SMARCA4 NM_001387283.1 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:4 B:1
• Conservation: PhyloP100: 9.29
• 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

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_001387283.1. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	SMARCA4	NM_001387283.1	MANE Plus Clinical	c.124A>G	p.Met42Val	missense	Exon 2 of 36	NP_001374212.1
	SMARCA4	NM_003072.5	MANE Select	c.124A>G	p.Met42Val	missense	Exon 2 of 35	NP_003063.2
	SMARCA4	NM_001128849.3		c.124A>G	p.Met42Val	missense	Exon 2 of 36	NP_001122321.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	SMARCA4	ENST00000646693.2	MANE Plus Clinical	c.124A>G	p.Met42Val	missense	Exon 2 of 36	ENSP00000495368.1
	SMARCA4	ENST00000344626.10	TSL:1 MANE Select	c.124A>G	p.Met42Val	missense	Exon 2 of 35	ENSP00000343896.4
	SMARCA4	ENST00000643549.1		c.124A>G	p.Met42Val	missense	Exon 2 of 35	ENSP00000493975.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000206 AC: 3 AN: 1458838 Hom.: 0 Cov.: 33 AF XY: 0.00000276 AC XY: 2 AN XY: 725612

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.00 AC: 0 AN: 33450

American (AMR) AF: 0.00 AC: 0 AN: 44442

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26014

East Asian (EAS) AF: 0.00 AC: 0 AN: 39652

South Asian (SAS) AF: 0.0000116 AC: 1 AN: 85870

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 52412

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5674

European-Non Finnish (NFE) AF: 0.00000180 AC: 2 AN: 1111100

Other (OTH) AF: 0.00 AC: 0 AN: 60224

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0.0136242), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 32

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000756

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

Oct 03, 2023

Baylor Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Aug 18, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces methionine, which is neutral and non-polar, with valine, which is neutral and non-polar, at codon 42 of the SMARCA4 protein (p.Met42Val). 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: 408644). Invitae Evidence 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 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.

Intellectual disability, autosomal dominant 16 Uncertain:1

Jul 15, 2021

Genome-Nilou Lab

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

not provided Uncertain:1

Jun 07, 2022

GeneDx

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant does not alter protein structure/function; Has not been previously published as pathogenic or benign to our knowledge

Hereditary cancer-predisposing syndrome Benign:1

Aug 05, 2022

Ambry Genetics

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

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 v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.13
BayesDel_addAF	Uncertain	0.14	D
BayesDel_noAF	Uncertain	-0.040
CADD	Uncertain	24
DANN	Uncertain	0.99
DEOGEN2	Uncertain	0.43	T
Eigen	Uncertain	0.31
Eigen_PC	Uncertain	0.42
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.97	D
M_CAP	Uncertain	0.24	D
MetaRNN	Uncertain	0.50	T
MetaSVM	Uncertain	0.14	D
MutationAssessor	Benign	1.1	L
PhyloP100		9.3
PrimateAI	Uncertain	0.72	T
PROVEAN	Benign	-1.7	N
REVEL	Uncertain	0.48
Sift	Uncertain	0.0040	D
Sift4G	Benign	0.064	T
Polyphen		0.32	B
Vest4		0.47
MutPred		0.20		Gain of glycosylation at S41 (P = 0.0454)
MVP		0.82
MPC		0.26
ClinPred		0.87	D
GERP RS		5.0
PromoterAI		0.014	Neutral
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.55
gMVP		0.38
Mutation Taster		=53/47	polymorphism

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: rs1060502081; hg19: chr19-11094951;