3-38630420-C-T

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PM1 PM2 PP2 PP3

The NM_001099404.2(SCN5A):c.283G>A(p.Val95Ile) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000137 in 1,608,614 control chromosomes in the GnomAD database, including 1 homozygotes. In-silico tool predicts a pathogenic 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. V95L) has been classified as Uncertain significance.

• Frequency:
  • Genomes: 𝑓 0.000020 (0 hom., cov: 32)
  • Exomes 𝑓: 0.000013 (1 hom.)
• Consequence: SCN5A NM_001099404.2 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1 U:5 O:1
• Conservation: PhyloP100: 7.90

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]

ACMG classification

Verdict is Likely_pathogenic. Variant got 6 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, 11 uncertain in NM_001099404.2
• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant where missense usually causes diseases, SCN5A
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.794

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
SCN5A	NM_001099404.2	c.283G>A	p.Val95Ile	missense_variant	3/28	ENST00000413689.6
SCN5A	NM_000335.5	c.283G>A	p.Val95Ile	missense_variant	3/28	ENST00000423572.7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
SCN5A	ENST00000413689.6	c.283G>A	p.Val95Ile	missense_variant	3/28	5	NM_001099404.2	P4
SCN5A	ENST00000423572.7	c.283G>A	p.Val95Ile	missense_variant	3/28	1	NM_000335.5	A1

Frequencies

GnomAD3 genomes AF: 0.0000197 AC: 3 AN: 152174 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: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000441

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.0000281 AC: 7 AN: 249414 Hom.: 1 AF XY: 0.00 AC XY: 0 AN XY: 135290

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.000166

Gnomad SAS exome AF: 0.0000653

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000177

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000130 AC: 19 AN: 1456324 Hom.: 1 Cov.: 28 AF XY: 0.00000552 AC XY: 4 AN XY: 724920

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.0000504

Gnomad4 SAS exome AF: 0.0000464

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000994

Gnomad4 OTH exome AF: 0.0000332

GnomAD4 genome AF: 0.0000197 AC: 3 AN: 152290 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 74456

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000441

Gnomad4 OTH AF: 0.00

Alfa AF: 0.0000673 Hom.: 1

Bravo AF: 0.0000416

ExAC AF: 0.0000330 AC: 4

EpiCase AF: 0.0000545

EpiControl AF: 0.00

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:1 Uncertain:5 Other:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Cardiac arrhythmia Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	All of Us Research Program, National Institutes of Health	Nov 02, 2023	This missense variant replaces valine with isoleucine at codon 95 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). An experimental functional study has shown that this variant does not change sodium channel function in vitro (PMID: 23805106). This variant has been identified in an individual affected with Brugada syndrome (PMID: 17081365, 20877689), in an individual affected with sudden death (PMID: 24529773), and in another individual affected with left ventricular noncompaction (PMID: 33500567). This variant has been identified in 7/249414 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. -
Uncertain significance, criteria provided, single submitter	clinical testing	Color Diagnostics, LLC DBA Color Health	May 26, 2023	This missense variant replaces valine with isoleucine at codon 95 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). An experimental functional study has shown that this variant does not change sodium channel function in vitro (PMID: 23805106). This variant has been identified in an individual affected with Brugada syndrome (PMID: 17081365, 20877689), in an individual affected with sudden death (PMID: 24529773), and in another individual affected with left ventricular noncompaction (PMID: 33500567). This variant has been identified in 7/249414 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 Uncertain:1 Other:1

Uncertain significance, criteria provided, single submitter	clinical testing	Invitae	Sep 01, 2022	This sequence change replaces valine, which is neutral and non-polar, with isoleucine, which is neutral and non-polar, at codon 95 of the SCN5A protein (p.Val95Ile). This variant is present in population databases (rs199473054, gnomAD 0.02%). This missense change has been observed in individual(s) with Brugada syndrome or left ventricular noncompaction cardiomyopathy (PMID: 20877689, 31397097, 33500567). ClinVar contains an entry for this variant (Variation ID: 67761). Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Benign"; Align-GVGD: "Class C25"). Experimental studies have shown that this missense change does not substantially affect SCN5A function (PMID: 23805106). 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. -
not provided, no classification provided	literature only	Cardiovascular Biomedical Research Unit, Royal Brompton & Harefield NHS Foundation Trust	-	This variant has been reported as associated with Brugada syndrome in the following publications (PMID:17081365;PMID:20877689). This is a literature report, and does not necessarily reflect the clinical interpretation of the Imperial College / Royal Brompton Cardiovascular Genetics laboratory. -

not provided Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

GeneDx

Nov 07, 2013

p.Val95Ile (GTA>ATA): c.283 G>A in exon 3 of the SCN5A gene (NM_198056.2) The Val95Ile variant in the SCN5A gene has been reported previously in one Chinese individual diagnosed with Brugada syndrome, who also harbored the Ala1649Val variant in SCN5A (Liang P et al., 2006). Both variants were inherited from this patient's father who was asymptomatic and had a normal ECG, however, suggesting that V95I may not be pathogenic (Liang P et al., 2006). Additionally, Val95Ile was reported in one individual from a cohort of 120 sudden adult death cases in the Han Chinese (Hou Y et al., 2013). Mutations in nearby residues (Phe93Ser, Ile94Ser, Arg104Gln) have been reported in association with Brugada syndrome, further supporting the functional importance of this region of the protein. Furthermore, the Val95Ile variant was not observed in approximately 6300 individuals of European and African American ancestry in the NHLBI Exome Sequencing Project, indicating it is not a common benign variant in these populations. However, one in vitro functional study showed that this variant does not affect sodium channel function (Gutter C et al., 2013). In summary, Val95Ile is a good candidate for a disease-causing mutation. The variant is found in ARRHYTHMIA panel(s). -

not specified Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Jan 10, 2017

Variant identified in a genome or exome case(s) and assessed due to predicted null impact of the variant or pathogenic assertions in the literature or databases. Disclaimer: This variant has not undergone full assessment. The following are preliminary notes: This variant has been reported in 3 papers in HGMD, classified as DM related to Brugada syndrome. It has been seen in affected and unaffected patients. It is classified in ClinVar with 1 star as Likely Pathogenic by GeneDx (in 2013). -

Brugada syndrome 1 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Mendelics

May 28, 2019

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.20
CardioboostArm	Pathogenic	0.99
CardioboostCm	Pathogenic	0.93
BayesDel_addAF	Pathogenic	0.22	D
BayesDel_noAF	Pathogenic	0.34
Cadd	Pathogenic	26
Dann	Uncertain	1.0
Eigen	Pathogenic	0.83
Eigen_PC	Pathogenic	0.79
FATHMM_MKL	Pathogenic	0.98	D
M_CAP	Pathogenic	0.70	D
MetaRNN	Pathogenic	0.79	D;D;D;D;D;D;D;D;D;D
MetaSVM	Pathogenic	1.1	D
MutationTaster	Benign	1.0	D;D;D;D;D;D;D;D;D;D
PrimateAI	Uncertain	0.75	T
PROVEAN	Benign	-0.95	N;N;N;N;N;N;N;N;N;.
REVEL	Pathogenic	0.86
Sift	Uncertain	0.016	D;D;D;D;D;D;D;D;D;.
Sift4G	Uncertain	0.026	D;D;D;D;D;D;D;D;D;D
Polyphen		1.0	D;D;.;D;.;D;D;.;.;.
Vest4		0.67
MutPred		0.76		Loss of catalytic residue at V95 (P = 0.0895);Loss of catalytic residue at V95 (P = 0.0895);Loss of catalytic residue at V95 (P = 0.0895);Loss of catalytic residue at V95 (P = 0.0895);Loss of catalytic residue at V95 (P = 0.0895);Loss of catalytic residue at V95 (P = 0.0895);Loss of catalytic residue at V95 (P = 0.0895);Loss of catalytic residue at V95 (P = 0.0895);Loss of catalytic residue at V95 (P = 0.0895);Loss of catalytic residue at V95 (P = 0.0895);
MVP		0.94
MPC		1.0
ClinPred		0.50	D
GERP RS		5.1
Varity_R		0.28
gMVP		0.72

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.070		Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Other links and lift over

dbSNP: rs199473054; hg19: chr3-38671911; COSMIC: COSV60067323; COSMIC: COSV60067323;