3-38562461-C-T

Variant names:

• chr3-38562461-C-T
• rs730880207
• NM_001099404.2:c.3917G>A

Variant summary

Our verdict is Likely pathogenic. The variant received 9 ACMG points: 9P and 0B. PM1 PM5 PP3_Strong PP5

The NM_001099404.2(SCN5A):​c.3917G>A​(p.Arg1306His) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000124 in 1,613,104 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 Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R1306C) has been classified as Uncertain significance.

• Frequency:
  • Genomes: 𝑓 0.000026 (0 hom., cov: 33)
  • Exomes 𝑓: 0.000011 (0 hom.)
• Consequence: SCN5A NM_001099404.2 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:2 U:6
• Conservation: PhyloP100: 7.91
• 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: Likely_pathogenic. The variant received 9 ACMG points.

• PM1: In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 10 uncertain in NM_001099404.2
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr3-38562461-C-A is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 519131.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.993
• PP5: Variant 3-38562461-C-T is Pathogenic according to our data. Variant chr3-38562461-C-T is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 180516.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
SCN5A	NM_001099404.2	c.3917G>A	p.Arg1306His	missense_variant	Exon 22 of 28	ENST00000413689.6	NP_001092874.1
SCN5A	NM_000335.5	c.3914G>A	p.Arg1305His	missense_variant	Exon 22 of 28	ENST00000423572.7	NP_000326.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
SCN5A	ENST00000413689.6	c.3917G>A	p.Arg1306His	missense_variant	Exon 22 of 28	5	NM_001099404.2	ENSP00000410257.1
SCN5A	ENST00000423572.7	c.3914G>A	p.Arg1305His	missense_variant	Exon 22 of 28	1	NM_000335.5	ENSP00000398266.2

Frequencies

GnomAD3 genomes AF: 0.0000263 AC: 4 AN: 152170 Hom.: 0 Cov.: 33

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: 0.0000588

Gnomad OTH AF: 0.00

GnomAD2 exomes AF: 0.00000405 AC: 1 AN: 247002 AF XY: 0.00000746

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: 0.0000110 AC: 16 AN: 1460934 Hom.: 0 Cov.: 31 AF XY: 0.0000124 AC XY: 9 AN XY: 726648

African (AFR) AF: 0.0000299 AC: 1 AN: 33472

American (AMR) AF: 0.00 AC: 0 AN: 44622

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26114

East Asian (EAS) AF: 0.00 AC: 0 AN: 39686

South Asian (SAS) AF: 0.0000349 AC: 3 AN: 85974

European-Finnish (FIN) AF: 0.0000187 AC: 1 AN: 53354

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5760

European-Non Finnish (NFE) AF: 0.00000990 AC: 11 AN: 1111614

Other (OTH) AF: 0.00 AC: 0 AN: 60338

GnomAD4 genome AF: 0.0000263 AC: 4 AN: 152170 Hom.: 0 Cov.: 33 AF XY: 0.0000135 AC XY: 1 AN XY: 74324

African (AFR) AF: 0.00 AC: 0 AN: 41448

American (AMR) AF: 0.00 AC: 0 AN: 15288

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

East Asian (EAS) AF: 0.00 AC: 0 AN: 5182

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

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10614

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

European-Non Finnish (NFE) AF: 0.0000588 AC: 4 AN: 68026

Other (OTH) AF: 0.00 AC: 0 AN: 2090

Alfa AF: 0.00000997 Hom.: 0

Bravo AF: 0.0000151

ExAC AF: 0.00000826 AC: 1

EpiCase AF: 0.00

EpiControl AF: 0.0000595

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:2 Uncertain:6

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Brugada syndrome Uncertain:2

Jul 10, 2014

Blueprint Genetics

Significance: Uncertain significance

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

Aug 13, 2022

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 1306 of the SCN5A protein (p.Arg1306His). This variant is present in population databases (rs730880207, gnomAD 0.0009%). This missense change has been observed in individual(s) with clinical features of Brugada syndrome and/or long QT syndrome (PMID: 33221895; Invitae). ClinVar contains an entry for this variant (Variation ID: 180516). 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 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. -

Cardiac arrhythmia Uncertain:2

Mar 10, 2025

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 1306 of the SCN5A protein. This variant is located within the conserved transmembrane domain DIII (a.a. 1201-1470) of the SCN5A protein. Rare non-truncating variants in this region have been shown to be significantly overrepresented in individuals with Brugada syndrome (PMID: 32893267). Computational prediction suggests that this variant may have a deleterious impact on protein structure and function. To our knowledge, functional studies have not been reported for this variant. This variant has been reported in a few individuals affected with Brugada syndrome (PMID: 32893267, 33221895, 36516610). This variant has been identified in 1/247002 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 15, 2023

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 histidine at codon 1306 of the SCN5A protein. Computational prediction suggests that this variant may have a 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 been reported in individuals affected with Brugada syndrome (PMID: 32893267, 33221895, 36516610). This variant has been identified in 1/247002 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 Pathogenic:1

Mar 31, 2022

Victorian Clinical Genetics Services, Murdoch Childrens Research Institute

Significance: Likely pathogenic

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 Likely pathogenic. 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 1 (SSS) (MIM#608567), whereas gain of function is usually associated with long QT syndrome-3 (LQTS) (MIM#603830). Dilated cardiomyopathy 1E (DCM) (MIM#601154) can be caused by variants with either a loss or gain of function mechanism (PMID: 29798782). (I) 0108 - This gene is associated with both recessive and dominant disease. Most conditions associated with this gene are dominantly inherited; however SSS is caused by biallelic variants (OMIM). (I) 0112 - The condition associated with this gene has incomplete penetrance (GeneReviews). (I) 0200 - Variant is predicted to result in a missense amino acid change from arginine to histidine. (I) 0251 - This variant is heterozygous. (I) 0302 - Variant is present in gnomAD (v3) <0.001 for a dominant condition (4 heterozygotes, 0 homozygotes). (SP) 0309 - Multiple alternative amino acid changes at the same position have been observed in gnomAD (v2 & v3) (highest allele count: 1 heterozygote, 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 Ion transport domain (DECIPHER). A review by Walsh, R. et al. (2021) determined that this transmembrane region is enriched for variants associated with Brugada syndrome, but not long QT syndrome (PMID: 32893267). (I) 0708 - Other missense variants comparable to the one identified in this case have conflicting previous evidence for pathogenicity. Substitutions to leucine, glycine, serine and cysteine have been reported as VUS in ClinVar, and the latter has been reclassified to likely pathogenic by a review utilising a disease-specific scheme modified from ACMG guidelines (PMID: 32893267). (I) 0808 - Previous reports of pathogenicity for this variant are conflicting. It has been reported five times as a VUS in association with both Brugada syndrome and arrhythmia in ClinVar, and Invitae specifies that it has been detected in an individual with features of long QT syndrome. In addition, a review utilising a disease-specific scheme modified from ACMG guidelines has reclassified this variant from VUS to likely pathogenic (PMID: 32893267). (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 Pathogenic:1

Aug 12, 2025

GeneDx

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; Not observed at significant frequency in large population cohorts (gnomAD); This variant is associated with the following publications: (PMID: 36516610, 34461752, 32893267, 37937776, 33221895, 38068978) -

SUDDEN INFANT DEATH SYNDROME;C1832680:Dilated cardiomyopathy 1E;C1837845:Sick sinus syndrome 1;C1859062:Long QT syndrome 3;C1879286:Progressive familial heart block, type 1A;C2751898:Ventricular fibrillation, paroxysmal familial, type 1;C3151464:Atrial fibrillation, familial, 10;C4551804:Brugada syndrome 1 Uncertain:1

Aug 16, 2021

Fulgent Genetics, Fulgent Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Cardiovascular phenotype Uncertain:1

Sep 04, 2024

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.R1306H variant (also known as c.3917G>A), located in coding exon 21 of the SCN5A gene, results from a G to A substitution at nucleotide position 3917. The arginine at codon 1306 is replaced by histidine, an amino acid with highly similar properties. This alteration has been reported in individuals from Brugada syndrome cohorts (Walsh R et al. Genet Med, 2021 01;23:47-58: Tarantino A at al. Int J Mol Sci. 2023 Nov;24(23)). 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 available evidence, the clinical significance of this variant remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.99
CardioboostArm	Pathogenic	1.0
CardioboostCm	Pathogenic	0.96
BayesDel_addAF	Pathogenic	0.56	D
BayesDel_noAF	Pathogenic	0.57
CADD	Pathogenic	30
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.99	.;.;.;.;.;D;.;.;.
Eigen	Pathogenic	0.83
Eigen_PC	Uncertain	0.56
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Pathogenic	0.99	.;D;D;D;D;D;D;.;D
M_CAP	Pathogenic	0.83	D
MetaRNN	Pathogenic	0.99	D;D;D;D;D;D;D;D;D
MetaSVM	Pathogenic	0.94	D
MutationAssessor	Pathogenic	5.4	.;.;.;.;.;H;.;.;.
PhyloP100		7.9
PrimateAI	Pathogenic	0.86	D
PROVEAN	Pathogenic	-4.4	D;D;D;D;D;D;D;D;D
REVEL	Pathogenic	0.87
Sift	Pathogenic	0.0	D;D;D;D;D;D;D;D;D
Sift4G	Pathogenic	0.0	D;D;D;D;D;D;D;D;D
Polyphen		1.0	D;D;.;D;.;D;D;.;.
Vest4		0.96
MutPred		0.93		Loss of methylation at R1306 (P = 0.0114);.;Loss of methylation at R1306 (P = 0.0114);Loss of methylation at R1306 (P = 0.0114);.;Loss of methylation at R1306 (P = 0.0114);.;.;.;
MVP		1.0
MPC		1.6
ClinPred		1.0	D
GERP RS		4.0
Varity_R		0.93
gMVP		0.99
Mutation Taster		=5/95	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: rs730880207; hg19: chr3-38603952;