chr19-10984154-G-A

Variant names:

• chr19-10984154-G-A
• NM_001387283.1:c.3G>A

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 3P and 0B. PVS1_Supporting PM2

The NM_003072.5(SMARCA4):​c.3G>A​(p.Met1?) variant causes a start lost change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000205 in 1,461,442 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000021 (0 hom.)
• Consequence: SMARCA4 NM_003072.5 start_lost
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:3
• Conservation: PhyloP100: 7.99

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 3 ACMG points.

• PVS1: Start lost variant, no pathogenic variants between lost start and next in-frame start position. Next in-frame start position is after 78 CDS bases. Genomic position: 10984229. Lost 0.016 part of the original CDS.
• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
SMARCA4	NM_001387283.1	c.3G>A	p.Met1?	start_lost	Exon 2 of 36	ENST00000646693.2	NP_001374212.1
SMARCA4	NM_003072.5	c.3G>A	p.Met1?	start_lost	Exon 2 of 35	ENST00000344626.10	NP_003063.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
SMARCA4	ENST00000646693.2	c.3G>A	p.Met1?	start_lost	Exon 2 of 36		NM_001387283.1	ENSP00000495368.1
SMARCA4	ENST00000344626.10	c.3G>A	p.Met1?	start_lost	Exon 2 of 35	1	NM_003072.5	ENSP00000343896.4
SMARCA4	ENST00000643549.1	c.3G>A	p.Met1?	start_lost	Exon 2 of 35			ENSP00000493975.1
SMARCA4	ENST00000541122.6	c.3G>A	p.Met1?	start_lost	Exon 3 of 35	5		ENSP00000445036.2
SMARCA4	ENST00000643296.1	c.3G>A	p.Met1?	start_lost	Exon 2 of 34			ENSP00000496635.1
SMARCA4	ENST00000644737.1	c.3G>A	p.Met1?	start_lost	Exon 2 of 34			ENSP00000495548.1
SMARCA4	ENST00000589677.5	c.3G>A	p.Met1?	start_lost	Exon 3 of 35	5		ENSP00000464778.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000205 AC: 3 AN: 1461442 Hom.: 0 Cov.: 33 AF XY: 0.00000275 AC XY: 2 AN XY: 727030

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: 0.00000270

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:3

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

Labcorp Genetics (formerly Invitae), Labcorp

Feb 14, 2021

This variant has not been reported in the literature in individuals with SMARCA4-related conditions. This sequence change affects the initiator methionine of the SMARCA4 mRNA. The next in-frame methionine is located at codon 27. This variant is not present in population databases (ExAC no frequency). Experimental studies and prediction algorithms are not available or were not evaluated, and the functional significance of this variant is currently unknown. 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. -

Neurodevelopmental disorder Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Laboratory of Molecular Genetics (Pr. Bezieau's lab), CHU de Nantes

Jul 02, 2021

- -

Hereditary cancer-predisposing syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Nov 21, 2024

The p.M1? variant (also known as c.3G>A) is located in coding exon 1 of the SMARCA4 gene and results from a G to A substitution at nucleotide position 3. This alters the methionine residue at the initiation codon (ATG). Variations that modify the initiation codon (ATG) are expected to result in either loss of translation initiation, N-terminal truncation, or cause a shift in the mRNA reading frame; however, there is an in-frame methionine 26 amino acids from the initiation site, which may result in N-terminal truncation of unknown functional significance. Based on the available evidence, the clinical significance of this variant remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Pathogenic	0.43
CADD	Uncertain	25
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.54	D;.;T;.;.;.;.;.;.;.;D;.;.;.;.;.;.;T;T
Eigen	Uncertain	0.47
Eigen_PC	Uncertain	0.56
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.90	.;D;.;.;.;.;D;.;.;.;D;D;.;D;D;D;D;D;D
M_CAP	Pathogenic	0.89	D
MetaRNN	Pathogenic	0.86	D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D
MetaSVM	Uncertain	0.45	D
PROVEAN	Benign	-1.6	N;.;.;.;.;.;.;.;.;.;N;.;.;N;.;N;.;N;N
REVEL	Pathogenic	0.78
Sift	Pathogenic	0.0	D;.;.;.;.;.;.;.;.;.;D;.;.;D;.;D;.;D;D
Sift4G	Pathogenic	0.0	D;.;.;.;.;.;.;.;.;.;D;.;.;D;D;D;D;D;D
Polyphen		0.53	P;.;P;.;.;.;.;.;.;.;P;.;.;.;.;.;.;.;P
Vest4		0.90
MutPred		0.99		Gain of catalytic residue at M1 (P = 0.102);Gain of catalytic residue at M1 (P = 0.102);Gain of catalytic residue at M1 (P = 0.102);Gain of catalytic residue at M1 (P = 0.102);Gain of catalytic residue at M1 (P = 0.102);Gain of catalytic residue at M1 (P = 0.102);Gain of catalytic residue at M1 (P = 0.102);Gain of catalytic residue at M1 (P = 0.102);Gain of catalytic residue at M1 (P = 0.102);Gain of catalytic residue at M1 (P = 0.102);Gain of catalytic residue at M1 (P = 0.102);Gain of catalytic residue at M1 (P = 0.102);Gain of catalytic residue at M1 (P = 0.102);Gain of catalytic residue at M1 (P = 0.102);Gain of catalytic residue at M1 (P = 0.102);Gain of catalytic residue at M1 (P = 0.102);Gain of catalytic residue at M1 (P = 0.102);Gain of catalytic residue at M1 (P = 0.102);Gain of catalytic residue at M1 (P = 0.102);
MVP		0.98
ClinPred		0.99	D
GERP RS		5.0
RBP_binding_hub_radar		0.92
RBP_regulation_power_radar		2.7
Varity_R		0.82
gMVP		0.52

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

No publications associated with this variant yet.

Other links and lift over

hg19: chr19-11094830;