chr3-38551478-G-A

Variant names:

• chr3-38551478-G-A
• rs878855292
• NM_001099404.2:c.4894C>T

Variant summary

Our verdict is Pathogenic. The variant received 18 ACMG points: 18P and 0B. PM1 PM2 PM5 PP3_Strong PP5_Very_Strong

The NM_001099404.2(SCN5A):​c.4894C>T​(p.Arg1632Cys) variant causes a missense change. The variant allele was found at a frequency of 0.00000248 in 1,613,886 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 15/24 in silico tools predict a damaging outcome for this variant. Variant has been reported in ClinVar as Pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R1632H) has been classified as Pathogenic.

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 31)
  • Exomes 𝑓: 0.0000021 (0 hom.)
• Consequence: SCN5A NM_001099404.2 missense
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:3
• Conservation: PhyloP100: 6.75
• Publications: 14 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: Pathogenic. The variant received 18 ACMG points.

• PM1: In a hotspot region, there are 5 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 13 uncertain in NM_001099404.2
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr3-38551477-C-T is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 67939.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.992
• PP5: Variant 3-38551478-G-A is Pathogenic according to our data. Variant chr3-38551478-G-A is described in ClinVar as Pathogenic. ClinVar VariationId is 242199.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_001099404.2. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	SCN5A	NM_001099404.2	MANE Plus Clinical	c.4894C>T	p.Arg1632Cys	missense	Exon 28 of 28	NP_001092874.1
	SCN5A	NM_000335.5	MANE Select	c.4891C>T	p.Arg1631Cys	missense	Exon 28 of 28	NP_000326.2
	SCN5A	NM_198056.3		c.4894C>T	p.Arg1632Cys	missense	Exon 28 of 28	NP_932173.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	SCN5A	ENST00000413689.6	TSL:5 MANE Plus Clinical	c.4894C>T	p.Arg1632Cys	missense	Exon 28 of 28	ENSP00000410257.1
	SCN5A	ENST00000423572.7	TSL:1 MANE Select	c.4891C>T	p.Arg1631Cys	missense	Exon 28 of 28	ENSP00000398266.2
	SCN5A	ENST00000333535.9	TSL:1	c.4894C>T	p.Arg1632Cys	missense	Exon 28 of 28	ENSP00000328968.4

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152096 Hom.: 0 Cov.: 31

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000147

Gnomad OTH AF: 0.00

GnomAD2 exomes AF: 0.00000398 AC: 1 AN: 251352 AF XY: 0.00

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000880

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000205 AC: 3 AN: 1461790 Hom.: 0 Cov.: 35 AF XY: 0.00000138 AC XY: 1 AN XY: 727182

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

American (AMR) AF: 0.00 AC: 0 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

East Asian (EAS) AF: 0.00 AC: 0 AN: 39700

South Asian (SAS) AF: 0.00 AC: 0 AN: 86258

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53410

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

European-Non Finnish (NFE) AF: 0.00000270 AC: 3 AN: 1111932

Other (OTH) AF: 0.00 AC: 0 AN: 60382

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152096 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 74302

African (AFR) AF: 0.00 AC: 0 AN: 41416

American (AMR) AF: 0.00 AC: 0 AN: 15262

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3468

East Asian (EAS) AF: 0.00 AC: 0 AN: 5174

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: 0.0000147 AC: 1 AN: 68016

Other (OTH) AF: 0.00 AC: 0 AN: 2094

Alfa AF: 0.0000170 Hom.: 0

Bravo AF: 0.00000378

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Pathogenic:2

Dec 12, 2024

GeneDx

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Published functional studies showed that p.(R1632C) resulted in loss of sodium channel availability (PMID: 26031372); Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; This variant is associated with the following publications: (PMID: 26031372, 30193851, 31191357, 33131149, 33221895, 30935997, 33164571, 30203441, 33797273, 26582918, 31928070, 27082542)

Dec 18, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

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 1632 of the SCN5A protein (p.Arg1632Cys). This variant is present in population databases (no rsID available, gnomAD 0.0009%). This missense change has been observed in individuals with autosomal dominant Brugada syndrome (PMID: 26031372, 27082542, 31191357). It has also been observed to segregate with disease in related individuals. ClinVar contains an entry for this variant (Variation ID: 242199). 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. Experimental studies have shown that this missense change affects SCN5A function (PMID: 26031372). For these reasons, this variant has been classified as Pathogenic.

Cardiovascular phenotype Pathogenic:1

Aug 12, 2025

Ambry Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.R1632C pathogenic mutation (also known as c.4894C>T), located in coding exon 27 of the SCN5A gene, results from a C to T substitution at nucleotide position 4894. The arginine at codon 1632 is replaced by cysteine, an amino acid with highly dissimilar properties. This variant was identified in one or more individuals with features consistent with Brugada syndrome (BrS) and segregated with disease in at least one family (Nakajima T et al. Heart Rhythm, 2015 Nov;12:2296-304; García-Molina E et al. Mol Med Rep, 2016 Jun;13:4677-80; Monasky MM et al. Front Physiol, 2019 May;10:666). Internal structural analysis indicates that the arginine impacted by this alteration is part of a highly conserved set of residues that generate a characteristic motif necessary to the function of voltage-sensing channels (Gandhi CS et al. J. Gen. Physiol., 2002 Oct;120:455-63; Starace DM et al. Nature, 2004 Feb;427:548-53). In vitro functional studies have indicated that this variant may impact channel kinetics, and a deep mutational scanning study categorized this alteration as a possible loss of function alteration (Nakajima T et al. Heart Rhythm, 2015 Nov;12:2296-304; Glazer AM et al. Circ Genom Precis Med, 2020 02;13:e002786). Other variant(s) at the same codon, p.R1632H, c.4895G>A and p.R1632L, c.4895G>T, have been identified in individual(s) with features consistent with Brugada syndrome (Benson DW et al. J. Clin. Invest. 2003;112:1019-28; Batchvarov VN et al. J Electrocardiol;44:308). This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Based on the supporting evidence, this variant is interpreted as a disease-causing mutation.

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	1.0
CardioboostArm	Pathogenic	1.0
CardioboostCm	Pathogenic	0.95
BayesDel_addAF	Pathogenic	0.57	D
BayesDel_noAF	Pathogenic	0.58
CADD	Pathogenic	33
DANN	Pathogenic	1.0
DEOGEN2	Pathogenic	0.99	D
Eigen	Pathogenic	1.0
Eigen_PC	Pathogenic	0.87
FATHMM_MKL	Pathogenic	0.97	D
LIST_S2	Pathogenic	0.99	D
M_CAP	Pathogenic	0.96	D
MetaRNN	Pathogenic	0.99	D
MetaSVM	Pathogenic	0.89	D
MutationAssessor	Pathogenic	5.2	H
PhyloP100		6.8
PrimateAI	Pathogenic	0.88	D
PROVEAN	Pathogenic	-7.4	D
REVEL	Pathogenic	0.97
Sift	Pathogenic	0.0	D
Sift4G	Pathogenic	0.0	D
Polyphen		1.0	D
Vest4		0.90
MutPred		0.95		Gain of methylation at R1629 (P = 0.0595)
MVP		0.98
MPC		1.7
ClinPred		1.0	D
GERP RS		4.5
Varity_R		0.93
gMVP		1.0
Mutation Taster		=0/100	disease causing (ClinVar)

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: rs878855292; hg19: chr3-38592969;