3-38551012-C-T

Variant summary

Our verdict is Likely benign. Variant got -5 ACMG points: 3P and 8B. PM1 PP2 BP4_Strong BS2

The NM_001099404.2(SCN5A):c.5360G>A(p.Ser1787Asn) variant causes a missense change. The variant allele was found at a frequency of 0.000495 in 1,614,018 control chromosomes in the GnomAD database, including 8 homozygotes. 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. S1787T) has been classified as Uncertain significance.

• Frequency:
  • Genomes: 𝑓 0.00062 (4 hom., cov: 31)
  • Exomes 𝑓: 0.00048 (4 hom.)
• Consequence: SCN5A NM_001099404.2 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1 U:5 B:11 O:1
• Conservation: PhyloP100: 6.11

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_benign. Variant got -5 ACMG points.

• PM1: In a hotspot region, there are 5 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 10 uncertain in NM_001099404.2
• PP2: Missense variant where missense usually causes diseases, SCN5A
• BP4: Computational evidence support a benign effect (MetaRNN=0.014260352).
• BS2: High Homozygotes in GnomAd at 4 SD gene

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
SCN5A	NM_001099404.2	c.5360G>A	p.Ser1787Asn	missense_variant	28/28	ENST00000413689.6
SCN5A	NM_000335.5	c.5357G>A	p.Ser1786Asn	missense_variant	28/28	ENST00000423572.7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
SCN5A	ENST00000413689.6	c.5360G>A	p.Ser1787Asn	missense_variant	28/28	5	NM_001099404.2	P4
SCN5A	ENST00000423572.7	c.5357G>A	p.Ser1786Asn	missense_variant	28/28	1	NM_000335.5	A1

Frequencies

GnomAD3 genomes AF: 0.000618 AC: 94 AN: 152124 Hom.: 4 Cov.: 31

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.0236

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.000118

Gnomad OTH AF: 0.00191

GnomAD3 exomes AF: 0.000905 AC: 227 AN: 250882 Hom.: 2 AF XY: 0.000788 AC XY: 107 AN XY: 135834

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.000145

Gnomad ASJ exome AF: 0.0193

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.000194

Gnomad OTH exome AF: 0.000982

GnomAD4 exome AF: 0.000482 AC: 705 AN: 1461894 Hom.: 4 Cov.: 35 AF XY: 0.000480 AC XY: 349 AN XY: 727248

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.000157

Gnomad4 ASJ exome AF: 0.0194

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.0000232

Gnomad4 FIN exome AF: 0.0000187

Gnomad4 NFE exome AF: 0.0000863

Gnomad4 OTH exome AF: 0.00151

GnomAD4 genome AF: 0.000618 AC: 94 AN: 152124 Hom.: 4 Cov.: 31 AF XY: 0.000673 AC XY: 50 AN XY: 74294

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.0236

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.000118

Gnomad4 OTH AF: 0.00191

Alfa AF: 0.00105 Hom.: 3

Bravo AF: 0.000586

TwinsUK AF: 0.000270 AC: 1

ALSPAC AF: 0.00 AC: 0

ESP6500AA AF: 0.00 AC: 0

ESP6500EA AF: 0.00105 AC: 9

ExAC AF: 0.000610 AC: 74

EpiCase AF: 0.000218

EpiControl AF: 0.000415

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:1 Uncertain:5 Benign:11 Other:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

not provided Benign:3 Other:1

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:10973849;PMID:15851227;PMID:16414944;PMID:19841300;PMID:20129283;PMID:22378279). -
Likely benign, criteria provided, single submitter	clinical testing	Invitae	Feb 01, 2024	- -
Likely benign, criteria provided, single submitter	clinical testing	GeneDx	Nov 10, 2020	This variant is associated with the following publications: (PMID: 20129283, 22378279, 26159999, 28988457, 30669290, 15851227, 23503384, 25923670, 16414944, 10973849, 24055113, 25637381, 27930354, 11463728, 22677073, 14753626, 28069705, 22373669, 27153395, 23861362, 30847666) -
Likely benign, criteria provided, single submitter	clinical testing	CeGaT Center for Human Genetics Tuebingen	Apr 01, 2024	SCN5A: PP3, BS2 -

Long QT syndrome Uncertain:1 Benign:2

Likely benign, no assertion criteria provided	research	CSER _CC_NCGL, University of Washington	Jun 01, 2014	- -
Likely benign, criteria provided, single submitter	research	Biesecker Lab/Clinical Genomics Section, National Institutes of Health	Jun 24, 2013	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Molecular Diagnostic Laboratory for Inherited Cardiovascular Disease, Montreal Heart Institute	-	- -

Brugada syndrome 1 Uncertain:1 Benign:1

Uncertain significance, criteria provided, single submitter	clinical testing	Illumina Laboratory Services, Illumina	Apr 27, 2017	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. -
Benign, criteria provided, single submitter	clinical testing	Mendelics	May 28, 2019	- -

not specified Benign:2

Likely benign, criteria provided, single submitter	clinical testing	Women's Health and Genetics/Laboratory Corporation of America, LabCorp	Nov 22, 2021	Variant summary: SCN5A c.5360G>A (p.Ser1787Asn) results in a conservative amino acid change in the encoded protein sequence. Four of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 0.00079 in 395574 control chromosomes, predominantly at a frequency of 0.02 within the Ashkenazi Jewish (ASJ) subpopulation in the gnomAD database, including 6 homozygotes. The observed variant frequency within ASJ control individuals in the gnomAD database is approximately 200-fold of the estimated maximal expected allele frequency for a pathogenic variant in SCN5A causing Arrhythmia phenotype (0.0001), strongly suggesting that the variant is a benign polymorphism. c.5360G>A has been reported in the literature in individuals affected with Arrhythmia (Splawski_2000, Zaklyazminskaya_2013), however it was also found in several healthy controls (e.g. Kapplinger_2010, Ackerman_2004, Ng_2013, Refsgaard_2012). These report(s) do not provide unequivocal conclusions about association of the variant with Cardiomyopathy. One publication reported experimental evidence evaluating an impact on protein function, and demonstrated that the molecular phenotype of the S1787N variant might depend upon both the splice variant background in which it is expressed and on the intracellular pH, i.e. the channel properties of the S1787N in the Q1077del background were altered under more acidic conditions (Hu_2015). These data however, do not allow convincing conclusions about the variant effect. Nine submitters have provided clinical-significance assessments for this variant in ClinVar after 2014 without evidence for independent evaluation, and classified the variant as VUS (n=2), likely benign (n=2) or benign (n=5). Based on the evidence outlined above, the variant was classified as likely benign. -
Benign, criteria provided, single submitter	clinical testing	Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine	Sep 10, 2019	proposed classification - variant undergoing re-assessment, contact laboratory -

Familial isolated arrhythmogenic right ventricular dysplasia Pathogenic:1

Pathogenic, flagged submission

research

Baylor-Hopkins Center for Mendelian Genomics, Johns Hopkins University School of Medicine

-

- -

Dilated cardiomyopathy 1E Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Apr 27, 2017

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. -

Ventricular fibrillation, paroxysmal familial, type 1 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Apr 27, 2017

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

Apr 27, 2017

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. -

Sick sinus syndrome 1 Benign:1

Benign, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Apr 27, 2017

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 was too high to be consistent with this variant causing disease. Therefore, this variant is classified as benign. -

Cardiovascular phenotype Benign:1

Benign, criteria provided, single submitter

clinical testing

Ambry Genetics

Dec 14, 2018

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

Benign, criteria provided, single submitter

clinical testing

Color Diagnostics, LLC DBA Color Health

Apr 07, 2018

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.42
CardioboostArm	Uncertain	0.56
CardioboostCm	Uncertain	0.76
BayesDel_addAF	Uncertain	0.059	T
BayesDel_noAF	Uncertain	0.11
Cadd	Uncertain	24
Dann	Uncertain	1.0
Eigen	Pathogenic	0.74
Eigen_PC	Pathogenic	0.69
FATHMM_MKL	Pathogenic	0.97	D
M_CAP	Pathogenic	0.75	D
MetaRNN	Benign	0.014	T;T;T;T;T;T;T;T;T
MetaSVM	Pathogenic	1.1	D
MutationTaster	Benign	1.0	D;D;D;D;D;D;D;D;D;D
PrimateAI	Pathogenic	0.81	D
PROVEAN	Benign	-2.3	N;N;N;N;N;N;N;N;N
REVEL	Pathogenic	0.86
Sift	Uncertain	0.0030	D;D;D;D;D;D;D;D;D
Sift4G	Uncertain	0.030	D;D;D;D;D;D;D;D;D
Polyphen		0.93	P;P;.;P;.;D;P;.;.
Vest4		0.38
MVP		0.82
MPC		1.4
ClinPred		0.13	T
GERP RS		4.8
Varity_R		0.72
gMVP		0.87

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: rs199473316; hg19: chr3-38592503; COSMIC: COSV61133113; COSMIC: COSV61133113;