rs756255060

Positions:

• chr19-11060147-C-A
• chr19-11060147-C-G
• chr19-11060147-C-T

Variant summary

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

The ENST00000344626.10(SMARCA4):​c.4871C>A​(p.Pro1624Gln) 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. P1624L) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 33)
• Consequence: SMARCA4 ENST00000344626.10 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• 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.4967C>A	p.Pro1656Gln	missense_variant	35/36	ENST00000646693.2	NP_001374212.1
SMARCA4	NM_003072.5	c.4871C>A	p.Pro1624Gln	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.4967C>A	p.Pro1656Gln	missense_variant	35/36		NM_001387283.1	ENSP00000495368
SMARCA4	ENST00000344626.10	c.4871C>A	p.Pro1624Gln	missense_variant	34/35	1	NM_003072.5	ENSP00000343896	P4

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 33

GnomAD4 genome Cov.: 33

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

Jun 21, 2020

Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be disruptive, but these predictions have not been confirmed by published functional studies and their clinical significance is uncertain. 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. This sequence change replaces proline with glutamine at codon 1656 of the SMARCA4 protein (p.Pro1656Gln). The proline residue is highly conserved and there is a moderate physicochemical difference between proline and glutamine. This variant is not present in population databases (ExAC no frequency). This variant has not been reported in the literature in individuals with SMARCA4-related conditions. -

Hereditary cancer-predisposing syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Jun 10, 2022

The p.P1656Q variant (also known as c.4967C>A), located in coding exon 34 of the SMARCA4 gene, results from a C to A substitution at nucleotide position 4967. The proline at codon 1656 is replaced by glutamine, 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). 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	Pathogenic	0.75
BayesDel_addAF	Pathogenic	0.24	D
BayesDel_noAF	Uncertain	0.11
CADD	Uncertain	24
DANN	Uncertain	0.99
DEOGEN2	Uncertain	0.47	T;.;T;.;.;.;.;.;.;.;T;.;.;.;.;.;T;T;.;.;.;.
Eigen	Uncertain	0.47
Eigen_PC	Uncertain	0.42
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.96	.;D;.;.;.;.;D;.;.;.;D;.;D;D;D;D;D;D;D;D;D;D
M_CAP	Pathogenic	0.46	D
MetaRNN	Uncertain	0.72	D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D
MetaSVM	Uncertain	0.52	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	-2.0	N;.;.;.;.;.;.;.;.;.;N;.;.;.;N;.;.;.;.;.;.;.
REVEL	Uncertain	0.56
Sift	Uncertain	0.0020	D;.;.;.;.;.;.;.;.;.;D;.;.;.;D;.;.;.;.;.;.;.
Sift4G	Benign	0.56	T;.;.;.;.;.;.;.;.;.;T;.;T;T;T;T;T;T;.;.;.;.
Polyphen		0.99	D;.;D;.;.;.;.;.;.;.;D;.;.;.;.;.;.;D;.;.;.;.
Vest4		0.55
MutPred		0.23		.;.;Gain of MoRF binding (P = 0.0584);.;.;.;.;.;.;.;.;.;.;.;.;.;.;Gain of MoRF binding (P = 0.0584);.;.;.;.;
MVP		0.83
MPC		2.0
ClinPred		0.95	D
GERP RS		3.5
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1
Varity_R		0.22
gMVP		0.73

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: rs756255060; hg19: chr19-11170823;