19-11060146-C-T

Position:

• chr19-11060146-C-T

Variant summary

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

The NM_001387283.1(SMARCA4):​c.4966C>T​(p.Pro1656Ser) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000143 in 1,398,814 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★★).

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: SMARCA4 NM_001387283.1 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:3
• Conservation: PhyloP100: 7.81

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.4966C>T	p.Pro1656Ser	missense_variant	35/36	ENST00000646693.2	NP_001374212.1
SMARCA4	NM_003072.5	c.4870C>T	p.Pro1624Ser	missense_variant	34/35	ENST00000344626.10	NP_003063.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
SMARCA4	ENST00000646693.2	c.4966C>T	p.Pro1656Ser	missense_variant	35/36		NM_001387283.1	ENSP00000495368
SMARCA4	ENST00000344626.10	c.4870C>T	p.Pro1624Ser	missense_variant	34/35	1	NM_003072.5	ENSP00000343896	P4

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 0.00000143 AC: 2 AN: 1398814 Hom.: 0 Cov.: 33 AF XY: 0.00000290 AC XY: 2 AN XY: 689964

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: 0.00000185

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Intellectual disability, autosomal dominant 16 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Genome-Nilou Lab

Jul 15, 2021

- -

Rhabdoid tumor predisposition syndrome 2 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Dec 24, 2023

This sequence change replaces proline, which is neutral and non-polar, with serine, which is neutral and polar, at codon 1656 of the SMARCA4 protein (p.Pro1656Ser). 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: 537822). 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) performed at Invitae indicates that this missense variant is expected to disrupt SMARCA4 protein function with a positive predictive value of 95%. 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

Mar 10, 2021

The p.P1656S variant (also known as c.4966C>T), located in coding exon 34 of the SMARCA4 gene, results from a C to T substitution at nucleotide position 4966. The proline at codon 1656 is replaced by serine, an amino acid with 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 syndromer 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	Pathogenic	0.68
BayesDel_addAF	Uncertain	0.11	D
BayesDel_noAF	Uncertain	-0.080
CADD	Uncertain	24
DANN	Pathogenic	1.0
DEOGEN2	Uncertain	0.44	T;.;T;.;.;.;.;.;.;.;T;.;.;.;.;.;T;T;.;.;.;.
Eigen	Uncertain	0.41
Eigen_PC	Uncertain	0.44
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.97	.;D;.;.;.;.;D;.;.;.;D;.;D;D;D;D;D;D;D;D;D;D
M_CAP	Pathogenic	0.42	D
MetaRNN	Uncertain	0.65	D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D
MetaSVM	Uncertain	0.36	D
MutationAssessor	Benign	1.8	L;.;.;.;.;.;.;.;.;.;L;.;.;.;.;.;.;.;.;.;.;.
MutationTaster	Benign	1.0	D;D;D;D;D;D;D;D;D
PrimateAI	Pathogenic	0.87	D
PROVEAN	Benign	-2.1	N;.;.;.;.;.;.;.;.;.;N;.;.;.;N;.;.;.;.;.;.;.
REVEL	Uncertain	0.46
Sift	Benign	0.077	T;.;.;.;.;.;.;.;.;.;T;.;.;.;T;.;.;.;.;.;.;.
Sift4G	Benign	0.77	T;.;.;.;.;.;.;.;.;.;T;.;T;T;T;T;T;T;.;.;.;.
Polyphen		0.79	P;.;D;.;.;.;.;.;.;.;P;.;.;.;.;.;.;D;.;.;.;.
Vest4		0.47
MutPred		0.28		.;.;Gain of phosphorylation at P1656 (P = 3e-04);.;.;.;.;.;.;.;.;.;.;.;.;.;.;Gain of phosphorylation at P1656 (P = 3e-04);.;.;.;.;
MVP		0.67
MPC		1.8
ClinPred		0.94	D
GERP RS		4.6
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.14
gMVP		0.74

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.030		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: rs1555796335; hg19: chr19-11170822; COSMIC: COSV60812057; COSMIC: COSV60812057;