19-10984159-C-A

Position:

• chr19-10984159-C-A

Variant summary

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

The NM_001387283.1(SMARCA4):​c.8C>A​(p.Thr3Asn) variant causes a missense change. The variant allele was found at a frequency of 0.000000684 in 1,461,432 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. T3I) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: SMARCA4 NM_001387283.1 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 6.08

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	UniProt
SMARCA4	NM_001387283.1	c.8C>A	p.Thr3Asn	missense_variant	2/36	ENST00000646693.2
SMARCA4	NM_003072.5	c.8C>A	p.Thr3Asn	missense_variant	2/35	ENST00000344626.10

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
SMARCA4	ENST00000646693.2	c.8C>A	p.Thr3Asn	missense_variant	2/36		NM_001387283.1
SMARCA4	ENST00000344626.10	c.8C>A	p.Thr3Asn	missense_variant	2/35	1	NM_003072.5	P4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461432 Hom.: 0 Cov.: 33 AF XY: 0.00000138 AC XY: 1 AN XY: 727036

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: 8.99e-7

Gnomad4 OTH exome AF: 0.00

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

Nov 29, 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. 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. 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 threonine, which is neutral and polar, with asparagine, which is neutral and polar, at codon 3 of the SMARCA4 protein (p.Thr3Asn). -

Hereditary cancer-predisposing syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

May 23, 2024

The p.T3N variant (also known as c.8C>A), located in coding exon 1 of the SMARCA4 gene, results from a C to A substitution at nucleotide position 8. The threonine at codon 3 is replaced by asparagine, 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	Uncertain	0.46
BayesDel_addAF	Uncertain	0.060	T
BayesDel_noAF	Benign	-0.15
CADD	Uncertain	24
DANN	Uncertain	0.98
DEOGEN2	Uncertain	0.42	T;.;T;.;.;.;.;.;.;.;T;.;.;.;.;.;.;T;T
Eigen	Uncertain	0.45
Eigen_PC	Uncertain	0.53
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.96	.;D;.;.;.;.;D;.;.;.;D;D;.;D;D;D;D;D;D
M_CAP	Uncertain	0.27	D
MetaRNN	Uncertain	0.44	T;T;T;T;T;T;T;T;T;T;T;T;T;T;T;T;T;T;T
MetaSVM	Uncertain	0.29	D
MutationAssessor	Benign	1.0	L;.;.;.;L;L;.;L;L;L;L;.;L;L;L;L;L;.;.
MutationTaster	Benign	1.0	D;D;D;D;D;D;D;D;D
PrimateAI	Uncertain	0.67	T
PROVEAN	Benign	-1.2	N;.;.;.;.;.;.;.;.;.;N;.;.;N;.;N;.;N;N
REVEL	Uncertain	0.44
Sift	Uncertain	0.0080	D;.;.;.;.;.;.;.;.;.;D;.;.;D;.;D;.;D;D
Sift4G	Uncertain	0.054	T;.;.;.;.;.;.;.;.;.;T;.;.;D;D;D;D;D;T
Polyphen		0.76	P;.;P;.;.;.;.;.;.;.;P;.;.;.;.;.;.;.;P
Vest4		0.48
MutPred		0.19		Loss of phosphorylation at T3 (P = 0.0012);Loss of phosphorylation at T3 (P = 0.0012);Loss of phosphorylation at T3 (P = 0.0012);Loss of phosphorylation at T3 (P = 0.0012);Loss of phosphorylation at T3 (P = 0.0012);Loss of phosphorylation at T3 (P = 0.0012);Loss of phosphorylation at T3 (P = 0.0012);Loss of phosphorylation at T3 (P = 0.0012);Loss of phosphorylation at T3 (P = 0.0012);Loss of phosphorylation at T3 (P = 0.0012);Loss of phosphorylation at T3 (P = 0.0012);Loss of phosphorylation at T3 (P = 0.0012);Loss of phosphorylation at T3 (P = 0.0012);Loss of phosphorylation at T3 (P = 0.0012);Loss of phosphorylation at T3 (P = 0.0012);Loss of phosphorylation at T3 (P = 0.0012);Loss of phosphorylation at T3 (P = 0.0012);Loss of phosphorylation at T3 (P = 0.0012);Loss of phosphorylation at T3 (P = 0.0012);
MVP		0.61
MPC		0.29
ClinPred		0.87	D
GERP RS		5.0
RBP_binding_hub_radar		0.97
RBP_regulation_power_radar		2.1
Varity_R		0.29
gMVP		0.18

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

No publications associated with this variant yet.

Other links and lift over

hg19: chr19-11094835;