chr19-11059871-G-C

Position:

• chr19-11059871-G-C

Variant summary

Our verdict is Likely benign. Variant got -5 ACMG points: 1P and 6B. PP2 BP4_Moderate BS2

The NM_001387283.1(SMARCA4):​c.4850G>C​(p.Gly1617Ala) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000821 in 1,461,598 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000082 (0 hom.)
• Consequence: SMARCA4 NM_001387283.1 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 3.31

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 -5 ACMG points.

• 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=0.2043879).
• BS2: High AC in GnomAdExome4 at 12 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
SMARCA4	NM_001387283.1	c.4850G>C	p.Gly1617Ala	missense_variant	34/36	ENST00000646693.2	NP_001374212.1
SMARCA4	NM_003072.5	c.4754G>C	p.Gly1585Ala	missense_variant	33/35	ENST00000344626.10	NP_003063.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
SMARCA4	ENST00000646693.2	c.4850G>C	p.Gly1617Ala	missense_variant	34/36		NM_001387283.1	ENSP00000495368
SMARCA4	ENST00000344626.10	c.4754G>C	p.Gly1585Ala	missense_variant	33/35	1	NM_003072.5	ENSP00000343896	P4

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD3 exomes AF: 0.00000805 AC: 2 AN: 248556 Hom.: 0 AF XY: 0.00 AC XY: 0 AN XY: 134560

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000579

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000821 AC: 12 AN: 1461598 Hom.: 0 Cov.: 32 AF XY: 0.00000688 AC XY: 5 AN XY: 727068

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.0000894

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.0000252

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000630

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

ExAC AF: 0.00000824 AC: 1

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

Jan 27, 2024

This sequence change replaces glycine, which is neutral and non-polar, with alanine, which is neutral and non-polar, at codon 1617 of the SMARCA4 protein (p.Gly1617Ala). This variant is present in population databases (rs148115492, gnomAD 0.006%). 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: 238487). 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 not expected to disrupt SMARCA4 protein function with a negative 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

Feb 28, 2024

The p.G1617A variant (also known as c.4850G>C), located in coding exon 33 of the SMARCA4 gene, results from a G to C substitution at nucleotide position 4850. The glycine at codon 1617 is replaced by alanine, an amino acid with 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 is unlikely. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.18
BayesDel_addAF	Benign	-0.043	T
BayesDel_noAF	Benign	-0.12
CADD	Uncertain	25
DANN	Uncertain	0.98
DEOGEN2	Benign	0.39	T;.;T;.;.;.;.;.;.;.;T;.;.;.;.;.;T;T;.;.;.;.
Eigen	Benign	-0.034
Eigen_PC	Benign	0.11
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Uncertain	0.88	.;D;.;.;.;.;D;.;.;.;D;.;D;D;D;D;D;D;D;D;D;D
M_CAP	Uncertain	0.16	D
MetaRNN	Benign	0.20	T;T;T;T;T;T;T;T;T;T;T;T;T;T;T;T;T;T;T;T;T;T
MetaSVM	Uncertain	-0.27	T
MutationAssessor	Benign	0.69	N;.;.;.;.;.;.;.;.;.;N;.;.;.;.;.;.;.;.;.;.;.
MutationTaster	Benign	1.0	D;D;D;D;D;D;D;D;D
PrimateAI	Uncertain	0.68	T
PROVEAN	Benign	-1.5	N;.;.;.;.;.;.;.;.;.;N;.;.;.;N;.;.;.;.;.;.;.
REVEL	Uncertain	0.39
Sift	Benign	0.082	T;.;.;.;.;.;.;.;.;.;T;.;.;.;T;.;.;.;.;.;.;.
Sift4G	Benign	0.14	T;.;.;.;.;.;.;.;.;.;T;.;T;T;T;T;T;T;.;.;.;.
Polyphen		0.21	B;.;B;.;.;.;.;.;.;.;B;.;.;.;.;.;.;B;.;.;.;.
Vest4		0.39
MutPred		0.13		.;.;Gain of helix (P = 0.0496);.;.;.;.;.;.;.;.;.;.;.;.;.;.;Gain of helix (P = 0.0496);.;.;.;.;
MVP		0.84
MPC		1.2
ClinPred		0.27	T
GERP RS		4.3
Varity_R		0.12
gMVP		0.59

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

Publications

LitVar

Other links and lift over

dbSNP: rs148115492; hg19: chr19-11170547;