rs878855295

Positions:

• chr3-38550619-T-C

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 5P and 2B. PM1 PM2 PP2 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. 13/22 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

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]

ACMG classification

Verdict is Uncertain_significance. Variant got 3 ACMG points.

• PM1: In a domain IQ (size 29) in uniprot entity SCN5A_HUMAN there are 5 pathogenic changes around while only 1 benign (83%) in NM_001099404.2
• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant in gene, where missense usually causes diseases (based on misZ statistic), SCN5A. . Gene score misZ 2.7504 (greater than the threshold 3.09). Trascript score misZ 4.7729 (greater than threshold 3.09). GenCC has associacion of gene with progressive familial heart block, type 1A, Brugada syndrome, familial sick sinus syndrome, short QT syndrome, paroxysmal familial ventricular fibrillation, progressive familial heart block, long QT syndrome 3, familial atrial fibrillation, catecholaminergic polymorphic ventricular tachycardia, dilated cardiomyopathy, dilated cardiomyopathy 1E, arrhythmogenic right ventricular cardiomyopathy, Brugada syndrome 1, atrial standstill, familial isolated dilated cardiomyopathy, familial long QT syndrome, sick sinus syndrome 1.
• BP4: Computational evidence support a benign effect (MetaRNN=0.13082996).

Transcripts

RefSeq

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

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
SCN5A	ENST00000413689.6	c.5753A>G	p.Gln1918Arg	missense_variant	28/28	5	NM_001099404.2	ENSP00000410257	P4
SCN5A	ENST00000423572.7	c.5750A>G	p.Gln1917Arg	missense_variant	28/28	1	NM_000335.5	ENSP00000398266	A1

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

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Dec 07, 2015

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
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;.;.;.
MutationTaster	Benign	0.52	D;D;D;D;D;D;N;N;N;N
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

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: rs878855295; hg19: chr3-38592110;