rs199473311

chr3-38551070-T-C

Variant summary

Our verdict is Pathogenic. Variant got 15 ACMG points: 15P and 0B. PM1 PM2 PP2 PP3_Moderate PP5_Very_Strong

The NM_001099404.2(SCN5A):c.5302A>G(p.Ile1768Val) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000658 in 151,934 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 Pathogenic (★★). Synonymous variant affecting the same amino acid position (i.e. I1768I) has been classified as Benign.

• Frequency: Genomes: 𝑓 0.0000066 (0 hom., cov: 31)
• Consequence: SCN5A NM_001099404.2 missense
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:4 O:1
• Conservation: PhyloP100: 8.00

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 15 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, 12 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, 0.921
• PP5: Variant 3-38551070-T-C is Pathogenic according to our data. Variant chr3-38551070-T-C is described in ClinVar as [Pathogenic]. Clinvar id is 67980.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr3-38551070-T-C is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
SCN5A	NM_001099404.2	c.5302A>G	p.Ile1768Val	missense_variant	28/28	ENST00000413689.6
SCN5A	NM_000335.5	c.5299A>G	p.Ile1767Val	missense_variant	28/28	ENST00000423572.7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
SCN5A	ENST00000413689.6	c.5302A>G	p.Ile1768Val	missense_variant	28/28	5	NM_001099404.2	P4
SCN5A	ENST00000423572.7	c.5299A>G	p.Ile1767Val	missense_variant	28/28	1	NM_000335.5	A1

Frequencies

GnomAD3 genomes AF: 0.00000658 AC: 1 AN: 151934 Hom.: 0 Cov.: 31

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.0000656

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: 0.00

Gnomad OTH AF: 0.00

GnomAD4 exome Cov.: 35

GnomAD4 genome AF: 0.00000658 AC: 1 AN: 151934 Hom.: 0 Cov.: 31 AF XY: 0.0000135 AC XY: 1 AN XY: 74196

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.0000656

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.00

Gnomad4 OTH AF: 0.00

Bravo AF: 0.00000378

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:4 Other:1

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Pathogenic:2

Pathogenic, criteria provided, single submitter	clinical testing	Invitae	Apr 05, 2021	For these reasons, this variant has been classified as Pathogenic. Experimental studies have shown that this missense change increases the rate of channel recovery from activation and decreases the speed of inactivation (PMID: 12209021, 12650885). This variant identified in the SCN5A gene is located in the transmembrane DIV-S6 region of the resulting protein (PMID: 25348405). For more information about the location of this variant, please visit www.invitae.com/SCN5A-topology. This variant has been reported in individuals and families affected with long QT syndrome (PMID: 12566525, 17088455, 17905336, 19841300, 21350584, 22373669). ClinVar contains an entry for this variant (Variation ID: 67980). This variant is not present in population databases (rs199473311, ExAC no frequency). This sequence change replaces isoleucine with valine at codon 1768 of the SCN5A protein (p.Ile1768Val). The isoleucine residue is highly conserved and there is a small physicochemical difference between isoleucine and valine. -
Pathogenic, criteria provided, single submitter	clinical testing	GeneDx	Nov 02, 2021	Not observed at significant frequency in large population cohorts (Lek et al., 2016); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; Published functional studies demonstrate a damaging effect as this variant results in an increased rate of recovery from the inactive channel state and subsequent channel reopening allowing persistent inward current (Rivolta et al., 2002; Groenewegen et al., 2003; Kauferstein et al., 2013); Reported in ClinVar as pathogenic (ClinVar Variant ID# 67980; Landrum et al., 2016); This variant is associated with the following publications: (PMID: 22581653, 12695286, 18929244, 12650885, 22370996, 12566525, 17905336, 17088455, 25804018, 31737537, 17556201, 12209021, 20513597, 22373669, 19841300) -

Long QT syndrome 3 Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Center for Human Genetics, Inc, Center for Human Genetics, Inc

Nov 01, 2016

- -

Cardiovascular phenotype Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Ambry Genetics

Jun 08, 2016

The p.I1768V pathogenic mutation (also known as c.5302A>G), located in coding exon 27 of the SCN5A gene, results from an A to G substitution at nucleotide position 5302. The isoleucine at codon 1768 is replaced by valine, an amino acid with highly similar properties. This alteration has been reported in a number of individuals diagnosed with long QT Syndrome (LQTS), and was shown to segregate with disease in one family (Rivolta I et al, Physiol. Genomics 2002 Sep; 10(3):191-7; Groenewegen WA et al, Cardiovasc. Res. 2003 Mar; 57(4):1072-8; Chung SK et al, Heart Rhythm 2007 Oct; 4(10):1306-14; Nannenberg EA et al, Circ Cardiovasc Genet 2012 Apr; 5(2):183-9; Kauferstein S et al, Int. J. Legal Med. 2013 Jan; 127(1):145-51). In addition, functional studies revealed that this alteration leads to altered recovery time from channel inactivation state (Rivolta I et al, Physiol. Genomics 2002 Sep; 10(3):191-7; Clancy CE et al, Circulation 2003 May; 107(17):2233-7; Groenewegen WA et al, Cardiovasc. Res. 2003 Mar; 57(4):1072-8; Kauferstein S et al, Int. J. Legal Med. 2013 Jan; 127(1):145-51). Based on the available evidence, p.I1768V is classified as a pathogenic mutation. -

Congenital long QT 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 Long QT syndrome in the following publications (PMID:12209021;PMID:12566525;PMID:17905336;PMID:19841300;PMID:22370996;PMID:22373669). 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	Uncertain	0.40
CardioboostArm	Pathogenic	1.0
CardioboostCm	Pathogenic	0.99
BayesDel_addAF	Pathogenic	0.53	D
BayesDel_noAF	Pathogenic	0.53
Cadd	Uncertain	25
Dann	Pathogenic	1.0
Eigen	Pathogenic	0.72
Eigen_PC	Pathogenic	0.69
FATHMM_MKL	Pathogenic	0.98	D
M_CAP	Pathogenic	0.86	D
MetaRNN	Pathogenic	0.92	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	Pathogenic	0.84	D
PROVEAN	Benign	-0.93	N;N;N;N;N;N;N;N;N
REVEL	Pathogenic	0.90
Sift	Pathogenic	0.0	D;D;D;D;D;D;D;D;D
Sift4G	Uncertain	0.022	D;D;D;D;D;D;D;D;D
Polyphen		1.0	D;D;.;D;.;D;D;.;.
Vest4		0.73
MutPred		0.85		.;.;Loss of catalytic residue at L1772 (P = 0.4161);.;.;Loss of catalytic residue at L1772 (P = 0.4161);.;.;.;
MVP		0.90
MPC		1.3
ClinPred		0.97	D
GERP RS		4.8
Varity_R		0.66
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: rs199473311; hg19: chr3-38592561;