rs199473044

chr3-38633256-G-A

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 7P and 1B. PM1 PM2 PM5 PP2 BP4

The NM_001099404.2(SCN5A):c.52C>T(p.Arg18Trp) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000159 in 1,612,938 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign 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. R18Q) has been classified as Uncertain significance.

• Frequency:
  • Genomes: 𝑓 0.000092 (0 hom., cov: 32)
  • Exomes 𝑓: 0.00017 (0 hom.)
• Consequence: SCN5A NM_001099404.2 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:9 B:6 O:1
• Conservation: PhyloP100: 3.50

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 topological_domain Cytoplasmic (size 130) in uniprot entity SCN5A_HUMAN there are 24 pathogenic changes around while only 8 benign (75%) 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 chr3-38633255-C-T is described in Lovd as [Pathogenic].
• PP2: Missense variant where missense usually causes diseases, SCN5A
• BP4: Computational evidence support a benign effect (MetaRNN=0.38248214).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
SCN5A	NM_001099404.2	c.52C>T	p.Arg18Trp	missense_variant	2/28	ENST00000413689.6
SCN5A	NM_000335.5	c.52C>T	p.Arg18Trp	missense_variant	2/28	ENST00000423572.7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
SCN5A	ENST00000413689.6	c.52C>T	p.Arg18Trp	missense_variant	2/28	5	NM_001099404.2	P4
SCN5A	ENST00000423572.7	c.52C>T	p.Arg18Trp	missense_variant	2/28	1	NM_000335.5	A1

Frequencies

GnomAD3 genomes AF: 0.0000920 AC: 14 AN: 152184 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.0000483

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.0000654

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00124

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000735

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.000270 AC: 67 AN: 248478 Hom.: 0 AF XY: 0.000378 AC XY: 51 AN XY: 134928

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 SAS exome AF: 0.00173

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.000106

Gnomad OTH exome AF: 0.000331

GnomAD4 exome AF: 0.000166 AC: 243 AN: 1460636 Hom.: 0 Cov.: 34 AF XY: 0.000228 AC XY: 166 AN XY: 726658

Gnomad4 AFR exome AF: 0.0000896

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00158

Gnomad4 FIN exome AF: 0.0000191

Gnomad4 NFE exome AF: 0.0000765

Gnomad4 OTH exome AF: 0.000199

GnomAD4 genome AF: 0.0000919 AC: 14 AN: 152302 Hom.: 0 Cov.: 32 AF XY: 0.000134 AC XY: 10 AN XY: 74472

Gnomad4 AFR AF: 0.0000481

Gnomad4 AMR AF: 0.0000653

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00125

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000735

Gnomad4 OTH AF: 0.00

Alfa AF: 0.000147 Hom.: 0

Bravo AF: 0.0000718

ExAC AF: 0.000331 AC: 40

Asia WGS AF: 0.000577 AC: 2 AN: 3478

EpiCase AF: 0.000164

EpiControl AF: 0.000237

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:9 Benign:6 Other:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

not provided Benign:2 Other:1

Likely benign, criteria provided, single submitter	clinical testing	Invitae	Jan 17, 2024	- -
not provided, no classification provided	literature only	Cardiovascular Biomedical Research Unit, Royal Brompton & Harefield NHS Foundation Trust	-	This variant has been reported in the following publications (PMID:15840476;PMID:19841300;PMID:20129283). -
Likely benign, criteria provided, single submitter	clinical testing	GeneDx	Aug 27, 2020	This variant is associated with the following publications: (PMID: 32048431, 28988457, 28600387, 25904541, 20129283, 15840476, 25351510, 19862833, 23805106, 29728395) -

not specified Uncertain:1 Benign:1

Benign, no assertion criteria provided	clinical testing	Stanford Center for Inherited Cardiovascular Disease, Stanford University	Jul 18, 2011	Note this variant was found in clinical genetic testing performed by one or more labs who may also submit to ClinVar. Thus any internal case data may overlap with the internal case data of other labs. The interpretation reviewed below is that of the Stanford Center for Inherited Cardiovascular Disease. p.Arg18Trp (c.52C>T) in the SCN5A gene Given the frequency in ancestry-matched unselected individuals and the very weak case data we consider this variant to be likely benign and we do not feel it is suitable for assessing risk in healthy relatives ("predictive genetic testing"). Tester et al (2005) observed the variant in 1 of 541 cases. This publication is a compendium of variants identified in cases referred to Dr. Ackerman's research lab for long QT genetic testing. No individual clinical or segregation data was provided. Of note when considering this paper, it is likely that ~25% of patients in this cohort did not actually have long QT syndrome (based on the reported yield). The variant was reported online in 39 of 59,815 individuals in the Exome Aggregation Consortium dataset (http://exac.broadinstitute.org/), which currently includes variant calls on ~64,000 individuals of European, African, Latino and Asian descent (as of July 21, 2015). The highest frequency was in 32 of 8254. The phenotype of those individuals is not publicly available. The dataset is comprised of multiple cohorts, some of which were recruited from the general population, others were enriched for common cardiovascular disease. -
Uncertain significance, criteria provided, single submitter	clinical testing	Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine	Apr 25, 2016	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: ExAC: 0.2% (32/16508) South Asian -

Brugada syndrome 1 Uncertain:1 Benign:1

Uncertain significance, criteria provided, single submitter	clinical testing	Illumina Laboratory Services, Illumina	May 08, 2019	This variant was observed as part of a predisposition screen in an ostensibly healthy population. A literature search was performed for the gene, cDNA change, and amino acid change (where applicable). Publications were found based on this search. However, the evidence from the literature, in combination with allele frequency data from public databases where available, was not sufficient to rule this variant in or out of causing disease. Therefore, this variant is classified as a variant of unknown significance. -
Benign, criteria provided, single submitter	clinical testing	Mendelics	Aug 22, 2023	- -

Ventricular fibrillation, paroxysmal familial, type 1 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

May 08, 2019

This variant was observed as part of a predisposition screen in an ostensibly healthy population. A literature search was performed for the gene, cDNA change, and amino acid change (where applicable). No publications were found based on this search. Allele frequency data from public databases did not allow this variant to be ruled in or out of causing disease. Therefore, this variant is classified as a variant of unknown significance. -

Dilated cardiomyopathy 1E Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

May 08, 2019

This variant was observed as part of a predisposition screen in an ostensibly healthy population. A literature search was performed for the gene, cDNA change, and amino acid change (where applicable). No publications were found based on this search. Allele frequency data from public databases did not allow this variant to be ruled in or out of causing disease. Therefore, this variant is classified as a variant of unknown significance. -

Arrhythmogenic right ventricular cardiomyopathy Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Molecular Diagnostic Laboratory for Inherited Cardiovascular Disease, Montreal Heart Institute

Jul 18, 2017

- -

Sick sinus syndrome 1 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

May 08, 2019

This variant was observed as part of a predisposition screen in an ostensibly healthy population. A literature search was performed for the gene, cDNA change, and amino acid change (where applicable). No publications were found based on this search. Allele frequency data from public databases did not allow this variant to be ruled in or out of causing disease. Therefore, this variant is classified as a variant of unknown significance. -

Progressive familial heart block, type 1A Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

May 08, 2019

This variant was observed as part of a predisposition screen in an ostensibly healthy population. A literature search was performed for the gene, cDNA change, and amino acid change (where applicable). No publications were found based on this search. Allele frequency data from public databases did not allow this variant to be ruled in or out of causing disease. Therefore, this variant is classified as a variant of unknown significance. -

Catecholaminergic polymorphic ventricular tachycardia 1 Uncertain:1

Uncertain significance, no assertion criteria provided

clinical testing

Blueprint Genetics

Oct 14, 2014

- -

Long QT syndrome 3 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

May 08, 2019

This variant was observed as part of a predisposition screen in an ostensibly healthy population. A literature search was performed for the gene, cDNA change, and amino acid change (where applicable). Publications were found based on this search. However, the evidence from the literature, in combination with allele frequency data from public databases where available, was not sufficient to rule this variant in or out of causing disease. Therefore, this variant is classified as a variant of unknown significance. -

Cardiovascular phenotype Benign:1

Benign, criteria provided, single submitter

clinical testing

Ambry Genetics

May 27, 2021

This alteration is classified as benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. -

Cardiac arrhythmia Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Color Diagnostics, LLC DBA Color Health

Oct 20, 2018

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.14
CardioboostArm	Uncertain	0.13
CardioboostCm	Benign	0.040
BayesDel_addAF	Benign	-0.056	T
BayesDel_noAF	Uncertain	0.13
Cadd	Benign	22
Dann	Pathogenic	1.0
Eigen	Uncertain	0.63
Eigen_PC	Uncertain	0.58
FATHMM_MKL	Uncertain	0.96	D
M_CAP	Pathogenic	0.64	D
MetaRNN	Benign	0.38	T;T;T;T;T;T;T;T;T;T;T
MetaSVM	Uncertain	0.61	D
MutationTaster	Benign	1.0	D;D;D;D;D;D;D;D;D;D
PrimateAI	Uncertain	0.55	T
PROVEAN	Pathogenic	-4.6	D;D;D;D;D;D;D;D;D;.;D
REVEL	Pathogenic	0.84
Sift	Uncertain	0.0070	D;D;D;D;D;D;D;D;D;.;D
Sift4G	Uncertain	0.059	T;T;T;T;T;T;T;T;T;D;.
Polyphen		0.99	D;D;.;D;.;D;D;.;.;.;.
Vest4		0.81
MVP		0.92
MPC		1.1
ClinPred		0.49	T
GERP RS		4.4
Varity_R		0.26
gMVP		0.64

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

Publications

LitVar

Other links and lift over

dbSNP: rs199473044; hg19: chr3-38674747; COSMIC: COSV60066899; COSMIC: COSV60066899;