rs878855295

Variant names:

• chr3-38550619-T-C
• rs878855295
• NM_001099404.2:c.5753A>G

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 4P and 2B. PM1 PM2 BP4_Moderate

The NM_001099404.2(SCN5A):​c.5753A>G​(p.Gln1918Arg) variant causes a missense 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. 14/24 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: not found (cov: 33)
• Consequence: SCN5A NM_001099404.2 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 1.86
• Publications: 0 publications found

Genes affected

SCN5A (HGNC:10593): (sodium voltage-gated channel alpha subunit 5) The protein encoded by this gene is an integral membrane protein and tetrodotoxin-resistant voltage-gated sodium channel subunit. This protein is found primarily in cardiac muscle and is responsible for the initial upstroke of the action potential in an electrocardiogram. Defects in this gene have been associated with long QT syndrome type 3 (LQT3), atrial fibrillation, cardiomyopathy, and Brugada syndrome 1, all autosomal dominant cardiac diseases. Alternative splicing results in several transcript variants encoding different isoforms. [provided by RefSeq, May 2022]

SCN5A Gene-Disease associations (from GenCC):

• Brugada syndrome

  Inheritance: AD Classification: DEFINITIVE, SUPPORTIVE Submitted by: ClinGen, Orphanet
• Brugada syndrome 1

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Ambry Genetics, Laboratory for Molecular Medicine, G2P, Genomics England PanelApp, Labcorp Genetics (formerly Invitae)
• dilated cardiomyopathy

  Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
• dilated cardiomyopathy 1E

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: G2P, Labcorp Genetics (formerly Invitae), Ambry Genetics
• familial long QT syndrome

  Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
• long QT syndrome 3

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae), G2P
• sick sinus syndrome 1

  Inheritance: AD, AR Classification: STRONG, LIMITED Submitted by: Labcorp Genetics (formerly Invitae)
• progressive familial heart block, type 1A

  Inheritance: SD, AD Classification: STRONG, MODERATE Submitted by: Ambry Genetics, Genomics England PanelApp
• atrial standstill

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• familial atrial fibrillation

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• familial isolated dilated cardiomyopathy

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• familial sick sinus syndrome

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• paroxysmal familial ventricular fibrillation

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• progressive familial heart block

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• arrhythmogenic right ventricular cardiomyopathy

  Inheritance: AD Classification: LIMITED Submitted by: ClinGen
• catecholaminergic polymorphic ventricular tachycardia

  Inheritance: AD Classification: NO_KNOWN Submitted by: ClinGen
• short QT syndrome

  Inheritance: AD Classification: NO_KNOWN Submitted by: ClinGen

ACMG classification

Our verdict: Uncertain_significance. The variant received 2 ACMG points.

• PM1: In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 26 uncertain in NM_001099404.2
• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.13082996).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
SCN5A	NM_001099404.2	c.5753A>G	p.Gln1918Arg	missense_variant	Exon 28 of 28	ENST00000413689.6	NP_001092874.1
SCN5A	NM_000335.5	c.5750A>G	p.Gln1917Arg	missense_variant	Exon 28 of 28	ENST00000423572.7	NP_000326.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
SCN5A	ENST00000413689.6	c.5753A>G	p.Gln1918Arg	missense_variant	Exon 28 of 28	5	NM_001099404.2	ENSP00000410257.1
SCN5A	ENST00000423572.7	c.5750A>G	p.Gln1917Arg	missense_variant	Exon 28 of 28	1	NM_000335.5	ENSP00000398266.2

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 33

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Uncertain:1

Dec 07, 2015

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

In summary, this is a novel missense change that is not predicted to affect protein function or cause disease. However the evidence is insufficient at this time to prove that conclusively. It has been classified as a Variant of Uncertain Significance. The arginine amino acid residue is found in multiple mammalian species, suggesting that this missense change does not adversely affect protein function. In addition, 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, but these predictions have not been confirmed by published functional studies. This variant is not present in population databases (ExAC no frequency) and has not been reported in the literature. This sequence change replaces glutamine with arginine at codon 1918 of the SCN5A protein (p.Gln1918Arg). The glutamine residue is moderately conserved and there is a small physicochemical difference between glutamine and arginine. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.10
CardioboostArm	Benign	0.000015
CardioboostCm	Benign	0.014
BayesDel_addAF	Uncertain	0.13	D
BayesDel_noAF	Uncertain	-0.060
CADD	Benign	16
DANN	Benign	0.92
DEOGEN2	Benign	0.34	.;.;.;.;.;T;.;.;.
Eigen	Benign	-0.67
Eigen_PC	Benign	-0.44
FATHMM_MKL	Benign	0.47	N
LIST_S2	Benign	0.75	.;T;T;T;T;T;T;.;T
M_CAP	Pathogenic	0.29	D
MetaRNN	Benign	0.13	T;T;T;T;T;T;T;T;T
MetaSVM	Uncertain	-0.18	T
MutationAssessor	Benign	-0.41	.;.;.;.;.;N;.;.;.
PhyloP100		1.9
PrimateAI	Benign	0.40	T
PROVEAN	Benign	0.67	N;N;N;N;N;N;N;N;N
REVEL	Uncertain	0.43
Sift	Benign	1.0	T;T;T;T;T;T;T;T;T
Sift4G	Benign	1.0	T;T;T;T;T;T;T;T;T
Polyphen		0.23	B;B;.;B;.;B;B;.;.
Vest4		0.11
MutPred		0.31		.;.;Gain of phosphorylation at S1920 (P = 0.0745);.;.;Gain of phosphorylation at S1920 (P = 0.0745);.;.;.;
MVP		0.87
MPC		0.55
ClinPred		0.076	T
GERP RS		3.7
Varity_R		0.23
gMVP		0.60
Mutation Taster		=51/49	polymorphism

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

Other links and lift over

dbSNP: rs878855295; hg19: chr3-38592110;