3-38560175-C-T

Variant names:

• chr3-38560175-C-T
• rs199473609
• NM_001099404.2:c.4217G>A

Variant summary

Our verdict is Likely pathogenic. The variant received 8 ACMG points: 8P and 0B. PM1 PM2 PP3_Strong

The NM_001099404.2(SCN5A):​c.4217G>A​(p.Gly1406Glu) variant causes a missense change. The variant allele was found at a frequency of 0.000000684 in 1,461,262 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic 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. G1406R) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: SCN5A NM_001099404.2 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:4 O:1
• Conservation: PhyloP100: 6.02
• Publications: 7 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 8 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, 10 uncertain in NM_001099404.2
• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.993

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
SCN5A	NM_001099404.2	c.4217G>A	p.Gly1406Glu	missense_variant	Exon 23 of 28	ENST00000413689.6	NP_001092874.1
SCN5A	NM_000335.5	c.4214G>A	p.Gly1405Glu	missense_variant	Exon 23 of 28	ENST00000423572.7	NP_000326.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
SCN5A	ENST00000413689.6	c.4217G>A	p.Gly1406Glu	missense_variant	Exon 23 of 28	5	NM_001099404.2	ENSP00000410257.1
SCN5A	ENST00000423572.7	c.4214G>A	p.Gly1405Glu	missense_variant	Exon 23 of 28	1	NM_000335.5	ENSP00000398266.2

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461262 Hom.: 0 Cov.: 32 AF XY: 0.00000138 AC XY: 1 AN XY: 726870

African (AFR) AF: 0.00 AC: 0 AN: 33466

American (AMR) AF: 0.00 AC: 0 AN: 44678

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26120

East Asian (EAS) AF: 0.00 AC: 0 AN: 39692

South Asian (SAS) AF: 0.00 AC: 0 AN: 86118

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53376

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5766

European-Non Finnish (NFE) AF: 9.00e-7 AC: 1 AN: 1111682

Other (OTH) AF: 0.00 AC: 0 AN: 60364

GnomAD4 genome Cov.: 33

Alfa AF: 0.00000506 Hom.: 0

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:4 Other:1

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Uncertain:2

May 14, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces glycine, which is neutral and non-polar, with glutamic acid, which is acidic and polar, at codon 1406 of the SCN5A protein (p.Gly1406Glu). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individual(s) with clinical features of Brugada syndrome (PMID: 20129283, 25904541, 32533946). ClinVar contains an entry for this variant (Variation ID: 67869). Advanced modeling performed at Invitae incorporating data from internal and/or published experimental studies (PMID: 32533946) indicates that this missense variant is expected to disrupt SCN5A function with a positive predictive value of 95%. Experimental studies have shown that this missense change affects SCN5A function (PMID: 32533946). 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. -

Sep 01, 2022

GeneDx

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Identified in at least two individuals referred for genetic testing for Brugada syndrome (Kapplinger et al., 2010); however, no clinical information was provided; 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; Published functional studies showed that p.(G1406E) resulted in a partial loss of peak current (Glazer et al., 2020); This variant is associated with the following publications: (PMID: 20129283, 30662450, 32569262, 31324802, 32533946) -

Cardiac arrhythmia Uncertain:2

Jun 15, 2023

Color Diagnostics, LLC DBA Color Health

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This missense variant replaces glycine with glutamic acid at codon 1406 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). Splice site prediction tools suggest that this variant may not impact RNA splicing. To our knowledge, functional studies have not been performed for this variant. This variant has been reported in 2 individuals referred for Brugada syndrome genetic testing (PMID: 20129283). This variant has not been identified 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. -

Jun 26, 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 glycine with glutamic acid at codon 1406 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). Splice site prediction tools suggest that this variant may not impact RNA splicing. To our knowledge, functional studies have not been performed for this variant. This variant has been reported in 2 individuals referred for Brugada syndrome genetic testing (PMID: 20129283). This variant has not been identified 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 Other:1

-

Cardiovascular Biomedical Research Unit, Royal Brompton & Harefield NHS Foundation Trust

Significance: not provided

Review Status: no classification provided

Collection Method: literature only

This variant has been reported as associated with Brugada syndrome in the following publications (PMID:20129283). This is a literature report, and does not necessarily reflect the clinical interpretation of the Imperial College / Royal Brompton Cardiovascular Genetics laboratory. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.99
CardioboostArm	Pathogenic	1.0
CardioboostCm	Pathogenic	0.99
BayesDel_addAF	Pathogenic	0.56	D
BayesDel_noAF	Pathogenic	0.56
CADD	Uncertain	26
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.97	.;.;.;.;.;D;.;.;.
Eigen	Pathogenic	0.94
Eigen_PC	Pathogenic	0.80
FATHMM_MKL	Pathogenic	0.97	D
LIST_S2	Uncertain	0.96	.;D;D;D;D;D;D;.;D
M_CAP	Pathogenic	0.95	D
MetaRNN	Pathogenic	0.99	D;D;D;D;D;D;D;D;D
MetaSVM	Pathogenic	1.0	D
MutationAssessor	Pathogenic	4.6	.;.;.;.;.;H;.;.;.
PhyloP100		6.0
PrimateAI	Pathogenic	0.92	D
PROVEAN	Pathogenic	-6.5	D;D;D;D;D;D;D;D;D
REVEL	Pathogenic	0.97
Sift	Uncertain	0.0010	D;D;D;D;D;D;D;D;D
Sift4G	Uncertain	0.0040	D;D;D;D;D;D;D;D;D
Polyphen		1.0	D;D;.;D;.;D;D;.;.
Vest4		0.98
MutPred		0.93		Loss of catalytic residue at G1406 (P = 0.0293);.;Loss of catalytic residue at G1406 (P = 0.0293);Loss of catalytic residue at G1406 (P = 0.0293);.;Loss of catalytic residue at G1406 (P = 0.0293);.;.;.;
MVP		0.99
MPC		1.6
ClinPred		1.0	D
GERP RS		4.3
Varity_R		0.94
gMVP		1.0
Mutation Taster		=0/100	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.060		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: rs199473609; hg19: chr3-38601666; COSMIC: COSV100346805;