chr19-10987746-G-C

Position:

• chr19-10987746-G-C

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 3P and 0B. PM2 PP2

The ENST00000344626.10(SMARCA4):​c.940G>C​(p.Ala314Pro) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. 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. A314T) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000021 (0 hom.)
  • Failed GnomAD Quality Control
• Consequence: SMARCA4 ENST00000344626.10 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 9.90

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.

• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant in gene, where missense usually causes diseases (based on misZ statistic), SMARCA4. . Gene score misZ 6.8459 (greater than the threshold 3.09). Trascript score misZ 8.7957 (greater than threshold 3.09). GenCC has associacion of gene with uterine corpus sarcoma, Coffin-Siris syndrome 1, intellectual disability, autosomal dominant 16, rhabdoid tumor predisposition syndrome 2, familial rhabdoid tumor, hereditary nonpolyposis colon cancer, Coffin-Siris syndrome.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
SMARCA4	NM_001387283.1	c.940G>C	p.Ala314Pro	missense_variant	6/36	ENST00000646693.2	NP_001374212.1
SMARCA4	NM_003072.5	c.940G>C	p.Ala314Pro	missense_variant	6/35	ENST00000344626.10	NP_003063.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
SMARCA4	ENST00000646693.2	c.940G>C	p.Ala314Pro	missense_variant	6/36		NM_001387283.1	ENSP00000495368
SMARCA4	ENST00000344626.10	c.940G>C	p.Ala314Pro	missense_variant	6/35	1	NM_003072.5	ENSP00000343896	P4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Data not reliable, filtered out with message: AS_VQSR AF: 0.00000212 AC: 3 AN: 1415730 Hom.: 0 Cov.: 33 AF XY: 0.00000284 AC XY: 2 AN XY: 704398

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: 0.00000186

Gnomad4 OTH exome AF: 0.0000171

GnomAD4 genome Cov.: 32

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

Labcorp Genetics (formerly Invitae), Labcorp

Apr 26, 2023

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. 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. ClinVar contains an entry for this variant (Variation ID: 2042993). This variant has not been reported in the literature in individuals affected with SMARCA4-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces alanine, which is neutral and non-polar, with proline, which is neutral and non-polar, at codon 314 of the SMARCA4 protein (p.Ala314Pro). -

Hereditary cancer-predisposing syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Oct 25, 2023

The p.A314P variant (also known as c.940G>C), located in coding exon 5 of the SMARCA4 gene, results from a G to C substitution at nucleotide position 940. The alanine at codon 314 is replaced by proline, 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). Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.30
BayesDel_addAF	Uncertain	0.13	D
BayesDel_noAF	Uncertain	-0.050
CADD	Uncertain	26
DANN	Uncertain	0.99
DEOGEN2	Uncertain	0.46	T;.;T;.;.;.;.;.;.;.;T;.;.;.;.;.;T;T
Eigen	Benign	-0.048
Eigen_PC	Benign	0.049
FATHMM_MKL	Pathogenic	1.0	D
LIST_S2	Uncertain	0.86	.;D;.;.;.;.;D;.;.;.;D;.;D;D;D;D;D;D
M_CAP	Pathogenic	0.39	D
MetaRNN	Uncertain	0.62	D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D
MetaSVM	Uncertain	-0.12	T
MutationAssessor	Benign	1.7	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	-2.1	N;.;.;.;.;.;.;.;.;.;N;.;N;.;N;.;N;N
REVEL	Uncertain	0.45
Sift	Benign	0.032	D;.;.;.;.;.;.;.;.;.;D;.;T;.;T;.;T;T
Sift4G	Benign	0.11	T;.;.;.;.;.;.;.;.;.;T;.;T;T;T;T;T;T
Polyphen		0.015	B;.;B;.;.;.;.;.;.;.;B;.;.;.;.;.;.;B
Vest4		0.51
MutPred		0.37		Gain of glycosylation at A314 (P = 0.0038);Gain of glycosylation at A314 (P = 0.0038);Gain of glycosylation at A314 (P = 0.0038);Gain of glycosylation at A314 (P = 0.0038);Gain of glycosylation at A314 (P = 0.0038);Gain of glycosylation at A314 (P = 0.0038);Gain of glycosylation at A314 (P = 0.0038);Gain of glycosylation at A314 (P = 0.0038);Gain of glycosylation at A314 (P = 0.0038);Gain of glycosylation at A314 (P = 0.0038);Gain of glycosylation at A314 (P = 0.0038);Gain of glycosylation at A314 (P = 0.0038);Gain of glycosylation at A314 (P = 0.0038);Gain of glycosylation at A314 (P = 0.0038);Gain of glycosylation at A314 (P = 0.0038);Gain of glycosylation at A314 (P = 0.0038);Gain of glycosylation at A314 (P = 0.0038);Gain of glycosylation at A314 (P = 0.0038);
MVP		0.80
MPC		0.34
ClinPred		0.94	D
GERP RS		4.4
Varity_R		0.45
gMVP		0.20

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.13		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: rs764188556; hg19: chr19-11098422;