rs45600438

Variant names:

• chr3-38603900-G-A
• rs45600438
• NM_001099404.2:c.1702C>T

Variant summary

Our verdict is Uncertain significance. The variant received 0 ACMG points: 0P and 0B.

The NM_001099404.2(SCN5A):​c.1702C>T​(p.Arg568Cys) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000124 in 1,613,798 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. R568H) has been classified as Uncertain significance.

• Frequency:
  • Genomes: 𝑓 0.000020 (0 hom., cov: 32)
  • Exomes 𝑓: 0.000012 (0 hom.)
• Consequence: SCN5A NM_001099404.2 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:5
• Conservation: PhyloP100: 2.29
• Publications: 4 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 0 ACMG points.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
SCN5A	NM_001099404.2	c.1702C>T	p.Arg568Cys	missense_variant	Exon 12 of 28	ENST00000413689.6	NP_001092874.1
SCN5A	NM_000335.5	c.1702C>T	p.Arg568Cys	missense_variant	Exon 12 of 28	ENST00000423572.7	NP_000326.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
SCN5A	ENST00000413689.6	c.1702C>T	p.Arg568Cys	missense_variant	Exon 12 of 28	5	NM_001099404.2	ENSP00000410257.1
SCN5A	ENST00000423572.7	c.1702C>T	p.Arg568Cys	missense_variant	Exon 12 of 28	1	NM_000335.5	ENSP00000398266.2

Frequencies

GnomAD3 genomes AF: 0.0000197 AC: 3 AN: 152164 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.000578

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.00

GnomAD2 exomes AF: 0.0000402 AC: 10 AN: 249022 AF XY: 0.0000518

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.000445

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000177

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000116 AC: 17 AN: 1461634 Hom.: 0 Cov.: 31 AF XY: 0.0000110 AC XY: 8 AN XY: 727114

African (AFR) AF: 0.00 AC: 0 AN: 33480

American (AMR) AF: 0.00 AC: 0 AN: 44720

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26128

East Asian (EAS) AF: 0.000176 AC: 7 AN: 39700

South Asian (SAS) AF: 0.0000116 AC: 1 AN: 86258

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53346

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 0.00000720 AC: 8 AN: 1111862

Other (OTH) AF: 0.0000166 AC: 1 AN: 60372

GnomAD4 genome AF: 0.0000197 AC: 3 AN: 152164 Hom.: 0 Cov.: 32 AF XY: 0.0000269 AC XY: 2 AN XY: 74336

African (AFR) AF: 0.00 AC: 0 AN: 41436

American (AMR) AF: 0.00 AC: 0 AN: 15282

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3472

East Asian (EAS) AF: 0.000578 AC: 3 AN: 5190

South Asian (SAS) AF: 0.00 AC: 0 AN: 4822

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10616

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 316

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 68026

Other (OTH) AF: 0.00 AC: 0 AN: 2092

Alfa AF: 0.00 Hom.: 0

ExAC AF: 0.0000578 AC: 7

EpiCase AF: 0.0000545

EpiControl AF: 0.00

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:5

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Cardiac arrhythmia Uncertain:2

May 08, 2023

Color Diagnostics, LLC DBA Color Health

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This missense variant replaces arginine with cysteine at codon 568 of the SCN5A protein. Computational prediction is inconclusive regarding the impact of this variant on protein structure and function (internally defined REVEL score threshold 0.5 < inconclusive < 0.7, PMID: 27666373). To our knowledge, functional studies have not been performed for this variant. This variant has been reported in two individuals affected with cardiovascular diseases (PMID: 31696929) and in another individual affected with dilated cardiomyopathy (PMID: 35284542). This variant has been identified in 13/280398 chromosomes in the general population by the Genome Aggregation Database (gnomAD). The available evidence is insufficient to determine the role of this variant in disease conclusively. Therefore, this variant is classified as a Variant of Uncertain Significance. -

Apr 16, 2024

All of Us Research Program, National Institutes of Health

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This missense variant replaces arginine with cysteine at codon 568 of the SCN5A protein. Computational prediction is inconclusive regarding the impact of this variant on protein structure and function (internally defined REVEL score threshold 0.5 < inconclusive < 0.7, PMID: 27666373). To our knowledge, functional studies have not been performed for this variant. This variant has been reported in two individuals affected with cardiovascular diseases (PMID: 31696929) and in another individual affected with dilated cardiomyopathy (PMID: 35284542). This variant has been identified in 13/280398 chromosomes in the general population by the Genome Aggregation Database (gnomAD). The available evidence is insufficient to determine the role of this variant in disease conclusively. Therefore, this variant is classified as a Variant of Uncertain Significance. -

Brugada syndrome 1 Uncertain:1

Oct 19, 2020

Victorian Clinical Genetics Services, Murdoch Childrens Research Institute

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Based on the classification scheme VCGS_Germline_v1.3.4, this variant is classified as 3B-VUS. Following criteria are met: 0103 - Loss of function and gain of function are both known mechanisms of disease in this gene. Loss of function is usually associated with Brugada syndrome 1 (MIM#601144) and sick sinus syndrome (SSS) (MIM#608567), whereas gain of function is usually associated with long QT syndrome (LQTS) (MIM#603830). Dilated cardiomyopathy 1E (DCM) (MIM#601154) can be caused by variants with either a loss of function or gain of function mechanism (PMID: 29798782). However, some variants simultaneously result in both a loss- of function and gain of function effect, and have been observed in patients with LQTS, Brugada syndrome or SSS, and patients with a blended phenotype. Additionally, different studies have shown conflicting mechanisms in association with atrial fibrillation (MIM#614022) (PMID: 29806494, PMID: 19167345, PMID: 26798387). (I) 0108 - This gene is associated with both recessive and dominant disease. Most conditions associated with this gene are dominantly inherited, however SSS can be caused by recessive variants (OMIM). (I) 0112 - The condition associated with this gene has incomplete penetrance. Among individuals with an SCN5A pathogenic variant, aproximately 20%-30% have an ECG diagnostic of Brugada syndrome and approximately 80% manifest the characteristic ECG changes when challenged with a sodium channel blocker (GeneReviews). (I) 0200 - Variant is predicted to result in a missense amino acid change from arginine to cysteine. (I) 0251 - This variant is heterozygous. (I) 0302 - Variant is present in gnomAD (v2) <0.001 for a dominant condition (13 heterozygotes, 0 homozygotes). (SP) 0309 - An alternative amino acid change at the same position has been observed in gnomAD (v2) (p.R568H: 6 heterozygotes, 0 homozygotes). (I) 0501 - Missense variant consistently predicted to be damaging by multiple in silico tools or highly conserved with a major amino acid change. (SP) 0600 - Variant is located in the annotated cytoplasmic domain of voltage-gated Na+ ion channel (NCBI conserved domain). (I) 0708 – Another missense variants comparable to the one identified in this case has conflicting previous evidence for pathogenicity. The p.R568H variant has been classified as a VUS by two clinical diagnostic laboratories and has been identified in healthy controls (ClinVar; PMID: 25904541). This variant has also been reported in one individual with LQTS whereby expression of the mutant channel in Xenopus oocytes resulted in faster inactivation kinetics and a positive shift in voltage-dependence of inactivation. However, the individual’s asymptomatic mother and brother also carried the p.R568H variant (PMID: 27287068). (I) 0809 - Previous evidence of pathogenicity for this variant is inconclusive. This variant has previously been reported as a variant of unknown significance by two clinical diagnostic laboratories (ClinVar). Additionally, it was identified in a review article which only used in silico analysis to predict the functional significance of the variant with no further evidence of pathogenicity (PMID: 19214780). (I) 0905 - No published segregation evidence has been identified for this variant. (I) 1007 - No published functional evidence has been identified for this variant. (I) 1208 - Inheritance information for this variant is not currently available in this individual. (I) Legend: (SP) - Supporting pathogenic, (I) - Information, (SB) - Supporting benign -

not provided Uncertain:1

Oct 30, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces arginine, which is basic and polar, with cysteine, which is neutral and slightly polar, at codon 568 of the SCN5A protein (p.Arg568Cys). This variant is present in population databases (rs45600438, gnomAD 0.06%). This missense change has been observed in individual(s) with dilated cardiomyopathy or epilepsy and/or peripartum cardiomyopathy (PMID: 20458009, 31696929, 35284542). ClinVar contains an entry for this variant (Variation ID: 846521). An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant is likely to be disruptive. 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. -

Cardiovascular phenotype Uncertain:1

Mar 20, 2018

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.R568C variant (also known as c.1702C>T), located in coding exon 11 of the SCN5A gene, results from a C to T substitution at nucleotide position 1702. The arginine at codon 568 is replaced by cysteine, an amino acid with highly dissimilar properties. Another alteration affecting the same amino acid, p.R568H (c.1703G>A), has been reported in association with long QT syndrome (LQTS) (Ortiz-Bonnin B et al. Pflugers Arch., 2016 Aug;468:1375-87). This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.13
CardioboostArm	Uncertain	0.29
CardioboostCm	Benign	0.0058
BayesDel_addAF	Uncertain	0.077	D
BayesDel_noAF	Pathogenic	0.20
CADD	Uncertain	24
DANN	Pathogenic	1.0
DEOGEN2	Pathogenic	0.89	.;.;.;.;.;D;.;.;.
Eigen	Uncertain	0.56
Eigen_PC	Uncertain	0.49
FATHMM_MKL	Uncertain	0.94	D
LIST_S2	Uncertain	0.92	.;D;D;D;D;D;D;.;D
M_CAP	Pathogenic	0.76	D
MetaRNN	Uncertain	0.45	T;T;T;T;T;T;T;T;T
MetaSVM	Pathogenic	0.88	D
MutationAssessor	Pathogenic	2.9	.;M;.;.;.;M;.;.;.
PhyloP100		2.3
PrimateAI	Benign	0.45	T
PROVEAN	Pathogenic	-5.8	D;D;D;D;D;D;D;D;D
REVEL	Pathogenic	0.68
Sift	Uncertain	0.0010	D;D;D;D;D;D;D;D;D
Sift4G	Uncertain	0.014	D;D;D;D;D;D;D;D;D
Polyphen		0.99	D;D;.;D;.;D;D;.;.
Vest4		0.52
MutPred		0.46		Loss of solvent accessibility (P = 0.0352);Loss of solvent accessibility (P = 0.0352);Loss of solvent accessibility (P = 0.0352);Loss of solvent accessibility (P = 0.0352);Loss of solvent accessibility (P = 0.0352);Loss of solvent accessibility (P = 0.0352);Loss of solvent accessibility (P = 0.0352);Loss of solvent accessibility (P = 0.0352);Loss of solvent accessibility (P = 0.0352);
MVP		0.89
MPC		1.1
ClinPred		0.75	D
GERP RS		4.1
Varity_R		0.29
gMVP		0.79
Mutation Taster		=19/81	disease causing

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: rs45600438; hg19: chr3-38645391; COSMIC: COSV100346031;