3-38554372-C-T

Variant summary

Our verdict is Pathogenic. Variant got 10 ACMG points: 10P and 0B. PM1 PM2 PP2 PP3_Strong PP5

The NM_001099404.2(SCN5A):c.4720G>A(p.Glu1574Lys) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,738 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 Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. E1574D) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 31)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: SCN5A NM_001099404.2 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1 U:1 O:1
• Conservation: PhyloP100: 7.86

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 Pathogenic. Variant got 10 ACMG points.

• PM1: In a helix (size 27) in uniprot entity SCN5A_HUMAN there are 7 pathogenic changes around while only 0 benign (100%) 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, 0.993
• PP5: Variant 3-38554372-C-T is Pathogenic according to our data. Variant chr3-38554372-C-T is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 67918.We mark this variant Likely_pathogenic, oryginal submissions are: {Likely_pathogenic=1, Uncertain_significance=1, not_provided=1}. Variant chr3-38554372-C-T is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
SCN5A	NM_001099404.2	c.4720G>A	p.Glu1574Lys	missense_variant	27/28	ENST00000413689.6
SCN5A	NM_000335.5	c.4717G>A	p.Glu1573Lys	missense_variant	27/28	ENST00000423572.7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
SCN5A	ENST00000413689.6	c.4720G>A	p.Glu1574Lys	missense_variant	27/28	5	NM_001099404.2	P4
SCN5A	ENST00000423572.7	c.4717G>A	p.Glu1573Lys	missense_variant	27/28	1	NM_000335.5	A1

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461738 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 727156

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 8.99e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 31

ClinVar

Significance: Conflicting classifications of pathogenicity

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

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Cardiovascular phenotype Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Ambry Genetics

Dec 21, 2021

The p.E1574K variant (also known as c.4720G>A), located in coding exon 26 of the SCN5A gene, results from a G to A substitution at nucleotide position 4720. The glutamic acid at codon 1574 is replaced by lysine, an amino acid with similar properties, and is located in the DIV-S2 transmembrane spanning region of the protein. This alteration was detected in an an individual reported to have Brugada syndrome (BrS) with type 1 ECG and inducible ventricular arrhythmia (Zumhagen S et al. Circ Arrhythm Electrophysiol. 2009;2:16-23; Gaborit N et al. Eur Heart J. 2009;30:487-96). This variant was also detected in additional individuals with BrS type 1 ECG, ventricular arrhythmia or syncope, and family history of sudden death in one kindred. The variant was also reportedly detected in several kindred members with spontaneous BrS type1 ECG as well as in some with normal baseline ECGs at the time of study (Ribeiro S et al. Rev Port Cardiol (Engl Ed). 2019 Jul;38(7):503-509). This variant has also been detected in individuals from BrS syndrome cohorts or cohorts referred for BrS genetic testing; however, clinical details were limited and some reports may overlap (Kapplinger JD et al. Heart Rhythm. 2010;7:33-46; Ciconte G et al. Eur Heart J. 2021 03;42(11):1082-1090; Walsh R et al. Genet Med. 2021 01;23(1):47-58). Based on internal structural analysis, this alteration disrupts a residue involved in the gating function of voltage-sensing domains (Seoh SA et al. Neuron. 1996 Jun;16(6):1159-67; Chamberlin A et al. J Mol Biol 2015;427(1):131-45; Ambry internal data). In one in vitro functional study, this variant resulted in reduced peak current density compared to wild type when expressed in the mock-homozygous state; however, the physiological relevance of this finding is unclear (Glazer AM. Am J Hum Genet. 2020 07;107(1):111-123). This variant is considered to be rare based on population cohorts in the Genome Aggregation Database (gnomAD). 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 majority of available evidence to date, this variant is likely to be pathogenic. -

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Jan 26, 2018

This sequence change replaces glutamic acid with lysine at codon 1574 of the SCN5A protein (p.Glu1574Lys). The glutamic acid residue is highly conserved and there is a small physicochemical difference between glutamic acid and lysine. This variant is not present in population databases (ExAC no frequency). This variant has been reported in individuals affected with Brugada syndrome (PMID:  19808440, 20129283). ClinVar contains an entry for this variant (Variation ID: 67918). 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, but these predictions have not been confirmed by published functional studies and their clinical significance is uncertain. 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. -

Brugada syndrome Other:1

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:19808440;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	0.96
CardioboostCm	Pathogenic	0.96
BayesDel_addAF	Pathogenic	0.58	D
BayesDel_noAF	Pathogenic	0.60
Cadd	Pathogenic	33
Dann	Pathogenic	1.0
Eigen	Pathogenic	0.84
Eigen_PC	Pathogenic	0.69
FATHMM_MKL	Pathogenic	0.98	D
M_CAP	Pathogenic	0.94	D
MetaRNN	Pathogenic	0.99	D;D;D;D;D;D;D;D
MetaSVM	Pathogenic	0.96	D
MutationTaster	Benign	1.0	D;D;D;D;D;D;D;D;D;D
PrimateAI	Uncertain	0.60	T
PROVEAN	Uncertain	-3.6	D;D;D;D;D;D;D;D
REVEL	Pathogenic	0.96
Sift	Pathogenic	0.0	D;D;D;D;D;D;D;D
Sift4G	Uncertain	0.0050	D;D;D;D;D;D;D;D
Polyphen		0.99	D;D;.;D;.;D;.;.
Vest4		0.99
MutPred		0.95		.;.;Gain of methylation at E1574 (P = 0.0115);.;.;Gain of methylation at E1574 (P = 0.0115);.;.;
MVP		0.96
MPC		0.92
ClinPred		1.0	D
GERP RS		3.7
Varity_R		0.97
gMVP		1.0

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.30		Details are displayed if max score is > 0.2
DS_DG_spliceai		0.30		Position offset: 3

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

Publications

LitVar

Other links and lift over

dbSNP: rs199473620; hg19: chr3-38595863;