19-11039552-A-G

Position:

• chr19-11039552-A-G

Variant summary

Our verdict is Likely benign. Variant got -1 ACMG points: 3P and 4B. PM2 PP2 BP4_Strong

The NM_001387283.1(SMARCA4):​c.4265A>G​(p.Lys1422Arg) variant causes a missense, splice region change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. 10/14 in silico tools predict a benign outcome for this variant. 2/3 splice prediction tools predict no significant impact on normal splicing. 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. K1422N) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 32)
• Consequence: SMARCA4 NM_001387283.1 missense, splice_region
• Scores: Splicing: ADA: 0.9622
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: -0.213

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 Likely_benign. Variant got -1 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.
• BP4: Computational evidence support a benign effect (MetaRNN=0.062357068).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
SMARCA4	NM_001387283.1	c.4265A>G	p.Lys1422Arg	missense_variant, splice_region_variant	30/36	ENST00000646693.2
SMARCA4	NM_003072.5	c.4171-1755A>G		intron_variant		ENST00000344626.10

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
SMARCA4	ENST00000646693.2	c.4265A>G	p.Lys1422Arg	missense_variant, splice_region_variant	30/36		NM_001387283.1
SMARCA4	ENST00000344626.10	c.4171-1755A>G		intron_variant		1	NM_003072.5	P4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 27

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

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jun 20, 2022

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. Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. 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 tolerated. ClinVar contains an entry for this variant (Variation ID: 470386). 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 lysine, which is basic and polar, with arginine, which is basic and polar, at codon 1422 of the SMARCA4 protein (p.Lys1422Arg). -

Hereditary cancer-predisposing syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Jul 13, 2022

The p.K1422R variant (also known as c.4265A>G), located in coding exon 29 of the SMARCA4 gene, results from an A to G substitution at nucleotide position 4265. The lysine at codon 1422 is replaced by arginine, an amino acid with highly similar properties. This amino acid position is conserved on limited sequence alignment. In addition, this alteration is predicted to be tolerated by in silico analysis. 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 is unlikely. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Benign	-0.28	T
BayesDel_noAF	Benign	-0.64
CADD	Benign	17
DANN	Benign	0.23
DEOGEN2	Benign	0.0059	.;T;.;.;T
Eigen	Benign	-1.3
Eigen_PC	Benign	-1.3
FATHMM_MKL	Benign	0.0014	N
LIST_S2	Benign	0.33	T;.;.;T;T
M_CAP	Uncertain	0.15	D
MetaRNN	Benign	0.062	T;T;T;T;T
MetaSVM	Benign	-0.83	T
MutationTaster	Benign	1.0	N;N;N;N;N;N;N;N;N
PrimateAI	Uncertain	0.63	T
Sift4G	Benign	0.70	.;.;.;.;T
Polyphen		0.044	.;B;.;.;B
Vest4		0.16
MutPred		0.24		.;Loss of ubiquitination at K1422 (P = 0.0107);.;.;Loss of ubiquitination at K1422 (P = 0.0107);
MVP		0.13
ClinPred		0.46	T
GERP RS		-0.59

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	0.96
dbscSNV1_RF	Benign	0.68
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

LitVar

Other links and lift over

dbSNP: rs1060502061; hg19: chr19-11150228;