19-10987785-C-G

Variant names:

• chr19-10987785-C-G
• rs770946823
• NM_001387283.1:c.979C>G

Variant summary

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

The NM_001387283.1(SMARCA4):​c.979C>G​(p.Pro327Ala) variant causes a missense change. The variant allele was found at a frequency of 0.000000691 in 1,448,010 control chromosomes in the GnomAD database, with no homozygous occurrence. 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. P327T) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.9e-7 (0 hom.)
• Consequence: SMARCA4 NM_001387283.1 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 4.79
• 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

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
SMARCA4	NM_001387283.1	c.979C>G	p.Pro327Ala	missense_variant	Exon 6 of 36	ENST00000646693.2	NP_001374212.1
SMARCA4	NM_003072.5	c.979C>G	p.Pro327Ala	missense_variant	Exon 6 of 35	ENST00000344626.10	NP_003063.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
SMARCA4	ENST00000646693.2	c.979C>G	p.Pro327Ala	missense_variant	Exon 6 of 36		NM_001387283.1	ENSP00000495368.1
SMARCA4	ENST00000344626.10	c.979C>G	p.Pro327Ala	missense_variant	Exon 6 of 35	1	NM_003072.5	ENSP00000343896.4
SMARCA4	ENST00000643549.1	c.979C>G	p.Pro327Ala	missense_variant	Exon 6 of 35			ENSP00000493975.1
SMARCA4	ENST00000541122.6	c.979C>G	p.Pro327Ala	missense_variant	Exon 7 of 35	5		ENSP00000445036.2
SMARCA4	ENST00000643296.1	c.979C>G	p.Pro327Ala	missense_variant	Exon 6 of 34			ENSP00000496635.1
SMARCA4	ENST00000644737.1	c.979C>G	p.Pro327Ala	missense_variant	Exon 6 of 34			ENSP00000495548.1
SMARCA4	ENST00000589677.5	c.979C>G	p.Pro327Ala	missense_variant	Exon 7 of 35	5		ENSP00000464778.1
SMARCA4	ENST00000643995.1	c.391C>G	p.Pro131Ala	missense_variant	Exon 3 of 32			ENSP00000496004.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.91e-7 AC: 1 AN: 1448010 Hom.: 0 Cov.: 34 AF XY: 0.00 AC XY: 0 AN XY: 719334

African (AFR) AF: 0.00 AC: 0 AN: 33154

American (AMR) AF: 0.00 AC: 0 AN: 43222

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 25766

East Asian (EAS) AF: 0.00 AC: 0 AN: 39004

South Asian (SAS) AF: 0.00 AC: 0 AN: 84838

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 50472

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5638

European-Non Finnish (NFE) AF: 9.04e-7 AC: 1 AN: 1106202

Other (OTH) AF: 0.00 AC: 0 AN: 59714

GnomAD4 genome Cov.: 32

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

Jul 24, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces proline, which is neutral and non-polar, with alanine, which is neutral and non-polar, at codon 327 of the SMARCA4 protein (p.Pro327Ala). 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: 2587143). 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

Aug 30, 2023

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.P327A variant (also known as c.979C>G), located in coding exon 5 of the SMARCA4 gene, results from a C to G substitution at nucleotide position 979. The proline at codon 327 is replaced by alanine, 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 syndrome is unlikely. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.18
BayesDel_addAF	Uncertain	0.077	D
BayesDel_noAF	Benign	-0.13
CADD	Uncertain	24
DANN	Uncertain	0.98
DEOGEN2	Uncertain	0.47	T;.;T;.;.;.;.;.;.;.;T;.;.;.;.;.;T;T
Eigen	Uncertain	0.20
Eigen_PC	Benign	0.21
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Uncertain	0.93	.;D;.;.;.;.;D;.;.;.;D;.;D;D;D;D;D;D
M_CAP	Pathogenic	0.31	D
MetaRNN	Uncertain	0.51	D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D
MetaSVM	Uncertain	0.55	D
MutationAssessor	Uncertain	2.0	M;.;.;.;M;M;.;M;M;M;M;M;M;M;M;M;.;.
PhyloP100		4.8
PrimateAI	Uncertain	0.75	T
PROVEAN	Benign	-2.3	N;.;.;.;.;.;.;.;.;.;N;.;N;.;N;.;N;N
REVEL	Uncertain	0.51
Sift	Benign	0.042	D;.;.;.;.;.;.;.;.;.;D;.;D;.;D;.;D;D
Sift4G	Benign	0.24	T;.;.;.;.;.;.;.;.;.;T;.;T;T;T;T;T;T
Polyphen		0.78	P;.;P;.;.;.;.;.;.;.;P;.;.;.;.;.;.;P
Vest4		0.49
MutPred		0.26		Loss of catalytic residue at P327 (P = 0.0188);Loss of catalytic residue at P327 (P = 0.0188);Loss of catalytic residue at P327 (P = 0.0188);Loss of catalytic residue at P327 (P = 0.0188);Loss of catalytic residue at P327 (P = 0.0188);Loss of catalytic residue at P327 (P = 0.0188);Loss of catalytic residue at P327 (P = 0.0188);Loss of catalytic residue at P327 (P = 0.0188);Loss of catalytic residue at P327 (P = 0.0188);Loss of catalytic residue at P327 (P = 0.0188);Loss of catalytic residue at P327 (P = 0.0188);Loss of catalytic residue at P327 (P = 0.0188);Loss of catalytic residue at P327 (P = 0.0188);Loss of catalytic residue at P327 (P = 0.0188);Loss of catalytic residue at P327 (P = 0.0188);Loss of catalytic residue at P327 (P = 0.0188);Loss of catalytic residue at P327 (P = 0.0188);Loss of catalytic residue at P327 (P = 0.0188);
MVP		0.65
MPC		0.31
ClinPred		0.66	D
GERP RS		4.3
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.12
gMVP		0.25
Mutation Taster		=33/67	disease causing

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: rs770946823; hg19: chr19-11098461;