3-38587413-C-T

Variant names:

• chr3-38587413-C-T
• rs199473160
• NM_001099404.2:c.2423G>A

Variant summary

Our verdict is Pathogenic. The variant received 10 ACMG points: 10P and 0B. PM1 PM2 PM5 PP3_Strong

The NM_001099404.2(SCN5A):​c.2423G>A​(p.Arg808His) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000342 in 1,460,462 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 16/24 in silico tools predict a damaging outcome for this variant. 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. R808C) has been classified as Likely pathogenic.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000034 (0 hom.)
• Consequence: SCN5A NM_001099404.2 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:5
• Conservation: PhyloP100: 7.91
• Publications: 17 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 10 ACMG points.

• PM1: In a hotspot region, there are 4 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 15 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 chr3-38587414-G-A is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 628262.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.979

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.2423G>A	p.Arg808His	missense	Exon 15 of 28	NP_001092874.1
	SCN5A	NM_000335.5	MANE Select	c.2423G>A	p.Arg808His	missense	Exon 15 of 28	NP_000326.2
	SCN5A	NM_198056.3		c.2423G>A	p.Arg808His	missense	Exon 15 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.2423G>A	p.Arg808His	missense	Exon 15 of 28	ENSP00000410257.1
	SCN5A	ENST00000423572.7	TSL:1 MANE Select	c.2423G>A	p.Arg808His	missense	Exon 15 of 28	ENSP00000398266.2
	SCN5A	ENST00000333535.9	TSL:1	c.2423G>A	p.Arg808His	missense	Exon 15 of 28	ENSP00000328968.4

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD2 exomes AF: 0.00000404 AC: 1 AN: 247724 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: 0.00000892

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000342 AC: 5 AN: 1460462 Hom.: 0 Cov.: 31 AF XY: 0.00000138 AC XY: 1 AN XY: 726324

African (AFR) AF: 0.00 AC: 0 AN: 33474

American (AMR) AF: 0.00 AC: 0 AN: 44648

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26074

East Asian (EAS) AF: 0.0000252 AC: 1 AN: 39678

South Asian (SAS) AF: 0.00 AC: 0 AN: 85992

European-Finnish (FIN) AF: 0.0000187 AC: 1 AN: 53350

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5748

European-Non Finnish (NFE) AF: 0.00000270 AC: 3 AN: 1111184

Other (OTH) AF: 0.00 AC: 0 AN: 60314

GnomAD4 genome Cov.: 33

Alfa AF: 0.0000868 Hom.: 0

Bravo AF: 0.00000378

ExAC AF: 0.0000165 AC: 2

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:5

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Cardiac arrhythmia Uncertain:2

Jul 27, 2021

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 histidine at codon 808 of the SCN5A protein. Computational prediction suggests that this variant may have deleterious impact on protein structure and function (internally defined REVEL score threshold >= 0.7, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has not been reported in individuals affected with cardiovascular disorders in the literature. This variant has been identified in 1/247724 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 27, 2023

All of Us Research Program, National Institutes of Health

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Brugada syndrome 1 Uncertain:1

Sep 22, 2024

Genomic Medicine Center of Excellence, King Faisal Specialist Hospital and Research Centre

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

not provided Uncertain:1

Dec 10, 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 histidine, which is basic and polar, at codon 808 of the SCN5A protein (p.Arg808His). This variant is present in population databases (rs199473160, gnomAD 0.0009%). This missense change has been observed in individual(s) with SCN5A-related conditions (PMID: 33662488). ClinVar contains an entry for this variant (Variation ID: 191501). 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. This variant disrupts the p.Arg808 amino acid residue in SCN5A. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 19406494). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. 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.

Long QT syndrome Uncertain:1

Jun 24, 2013

Biesecker Lab/Clinical Genomics Section, National Institutes of Health

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: research

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.78
CardioboostArm	Pathogenic	1.0
CardioboostCm	Pathogenic	0.96
BayesDel_addAF	Pathogenic	0.57	D
BayesDel_noAF	Pathogenic	0.59
CADD	Pathogenic	31
DANN	Pathogenic	1.0
DEOGEN2	Pathogenic	0.98	D
Eigen	Pathogenic	0.93
Eigen_PC	Pathogenic	0.81
FATHMM_MKL	Pathogenic	1.0	D
LIST_S2	Uncertain	0.96	D
M_CAP	Pathogenic	0.91	D
MetaRNN	Pathogenic	0.98	D
MetaSVM	Pathogenic	1.0	D
MutationAssessor	Pathogenic	4.3	H
PhyloP100		7.9
PrimateAI	Pathogenic	0.84	D
PROVEAN	Pathogenic	-5.0	D
REVEL	Pathogenic	0.96
Sift	Pathogenic	0.0	D
Sift4G	Uncertain	0.0080	D
Polyphen		0.99	D
Vest4		0.99
MutPred		0.85		Loss of loop (P = 0.0203)
MVP		0.99
MPC		1.1
ClinPred		1.0	D
GERP RS		4.3
Varity_R		0.90
gMVP		0.97
Mutation Taster		=3/97	disease causing

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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: rs199473160; hg19: chr3-38628904; COSMIC: COSV61137106;