rs199473094

Variant summary

Our verdict is Uncertain significance. The variant received 3 ACMG points: 3P and 0B. PM1PP3

The NM_001099404.2(SCN5A):​c.1018C>T​(p.Arg340Trp) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000118 in 1,613,464 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 Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R340Q) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 33)
Exomes 𝑓: 0.000012 ( 0 hom. )

Consequence

SCN5A
NM_001099404.2 missense

Scores

6
3
12

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:6O:1

Conservation

PhyloP100: 1.53

Publications

6 publications found
Variant links:
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]
SCN5A Gene-Disease associations (from GenCC):
  • Brugada syndrome
    Inheritance: AD Classification: DEFINITIVE, SUPPORTIVE Submitted by: ClinGen, Orphanet
  • Brugada syndrome 1
    Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Ambry Genetics, Laboratory for Molecular Medicine, G2P, Genomics England PanelApp, Labcorp Genetics (formerly Invitae)
  • dilated cardiomyopathy
    Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
  • dilated cardiomyopathy 1E
    Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: G2P, Labcorp Genetics (formerly Invitae), Ambry Genetics
  • familial long QT syndrome
    Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
  • long QT syndrome 3
    Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae), G2P
  • sick sinus syndrome 1
    Inheritance: AD, AR Classification: STRONG, LIMITED Submitted by: Labcorp Genetics (formerly Invitae)
  • progressive familial heart block, type 1A
    Inheritance: SD, AD Classification: STRONG, MODERATE Submitted by: Ambry Genetics, Genomics England PanelApp
  • atrial standstill
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
  • familial atrial fibrillation
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
  • familial isolated dilated cardiomyopathy
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
  • familial sick sinus syndrome
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
  • paroxysmal familial ventricular fibrillation
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
  • progressive familial heart block
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
  • arrhythmogenic right ventricular cardiomyopathy
    Inheritance: AD Classification: LIMITED Submitted by: ClinGen
  • catecholaminergic polymorphic ventricular tachycardia
    Inheritance: AD Classification: NO_KNOWN Submitted by: ClinGen
  • short QT syndrome
    Inheritance: AD Classification: NO_KNOWN Submitted by: ClinGen

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 3 ACMG points.

PM1
In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 11 uncertain in NM_001099404.2
PP3
MetaRNN computational evidence supports a deleterious effect, 0.761

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
SCN5ANM_001099404.2 linkc.1018C>T p.Arg340Trp missense_variant Exon 9 of 28 ENST00000413689.6 NP_001092874.1 Q14524H9KVD2
SCN5ANM_000335.5 linkc.1018C>T p.Arg340Trp missense_variant Exon 9 of 28 ENST00000423572.7 NP_000326.2 Q14524-2Q86V90

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
SCN5AENST00000413689.6 linkc.1018C>T p.Arg340Trp missense_variant Exon 9 of 28 5 NM_001099404.2 ENSP00000410257.1 H9KVD2
SCN5AENST00000423572.7 linkc.1018C>T p.Arg340Trp missense_variant Exon 9 of 28 1 NM_000335.5 ENSP00000398266.2 Q14524-2

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152260
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.0000241
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:
0.00
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.00000402
AC:
1
AN:
248454
AF XY:
0.00
show subpopulations
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 FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00000888
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000123
AC:
18
AN:
1461204
Hom.:
0
Cov.:
31
AF XY:
0.00000963
AC XY:
7
AN XY:
726852
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33480
American (AMR)
AF:
0.00
AC:
0
AN:
44712
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26110
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39696
South Asian (SAS)
AF:
0.0000116
AC:
1
AN:
86234
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53170
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5766
European-Non Finnish (NFE)
AF:
0.0000153
AC:
17
AN:
1111676
Other (OTH)
AF:
0.00
AC:
0
AN:
60360
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.478
Heterozygous variant carriers
0
2
4
5
7
9
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
GnomAD4 genome
AF:
0.00000657
AC:
1
AN:
152260
Hom.:
0
Cov.:
33
AF XY:
0.0000134
AC XY:
1
AN XY:
74384
show subpopulations
African (AFR)
AF:
0.0000241
AC:
1
AN:
41474
American (AMR)
AF:
0.00
AC:
0
AN:
15288
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5198
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4834
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10628
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
68046
Other (OTH)
AF:
0.00
AC:
0
AN:
2092
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.425
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
Alfa
AF:
0.0000378
Hom.:
0
Bravo
AF:
0.0000227
TwinsUK
AF:
0.00
AC:
0
ALSPAC
AF:
0.000259
AC:
1
ExAC
AF:
0.0000165
AC:
2

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:6Other:1
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not provided Uncertain:3
Jan 25, 2021
GeneDx
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Not observed at a significant frequency in large population cohorts (Lek et al., 2016); In silico analysis supports that this missense variant does not alter protein structure/function; This variant is associated with the following publications: (PMID: 24606995, 19716085, 19862833, 18822425, 22581653, 28150151) -

Oct 29, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces arginine, which is basic and polar, with tryptophan, which is neutral and slightly polar, at codon 340 of the SCN5A protein (p.Arg340Trp). The frequency data for this variant in the population databases is considered unreliable, as metrics indicate poor data quality at this position in the gnomAD database. This missense change has been observed in individual(s) with Romano-Ward syndrome (PMID: 19862833). ClinVar contains an entry for this variant (Variation ID: 67625). An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant is likely to be tolerated. 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. -

Nov 02, 2021
AiLife Diagnostics, AiLife Diagnostics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

not specified Uncertain:1
Jan 16, 2024
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Variant summary: SCN5A c.1018C>T (p.Arg340Trp) results in a non-conservative amino acid change in the encoded protein sequence. Three of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 4e-06 in 248454 control chromosomes (gnomAD). The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. c.1018C>T has been reported in the literature in individuals affected with Long QT Syndrome without strong evidence of causality (e.g. Kapplinger_2009, Hedley_2009, Goldenberg_2011, Wilde_2016). These reports do not provide unequivocal conclusions about association of the variant with Long QT Syndrome. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. The following publications have been ascertained in the context of this evaluation (PMID: 19716085, 27566755, 19862833, 21185501). ClinVar contains an entry for this variant (Variation ID: 67625). Based on the evidence outlined above, the variant was classified as uncertain significance. -

Cardiovascular phenotype Uncertain:1
May 04, 2022
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The c.1018C>T (p.R340W) alteration is located in exon 9 (coding exon 8) of the SCN5A gene. This alteration results from a C to T substitution at nucleotide position 1018, causing the arginine (R) at amino acid position 340 to be replaced by a tryptophan (W). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Cardiac arrhythmia Uncertain:1
Feb 29, 2024
Color Diagnostics, LLC DBA Color Health
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This missense variant replaces arginine with tryptophan at codon 340 of the SCN5A protein. Computational prediction is inconclusive regarding the impact of this variant on protein structure and function (internally defined REVEL score threshold 0.5 < inconclusive < 0.7, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has been reported in at least four unrelated individuals affected with long QT syndrome (PMID: 18822425, 19716085, 21185501, 24606995, 27566755, 32893267). This variant has been identified in 2/279848 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. -

Congenital long QT syndrome Other:1
-
Cardiovascular Biomedical Research Unit, Royal Brompton & Harefield NHS Foundation Trust
Significance:not provided
Review Status:no classification provided
Collection Method:literature only

This variant has been reported as associated with Long QT syndrome in the following publications (PMID:19716085;PMID:19862833). 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
Benign
0.14
CardioboostArm
Benign
0.030
CardioboostCm
Benign
0.013
BayesDel_addAF
Pathogenic
0.30
D
BayesDel_noAF
Pathogenic
0.19
CADD
Uncertain
24
DANN
Uncertain
1.0
DEOGEN2
Pathogenic
0.82
.;.;.;.;.;D;.;.;.
Eigen
Benign
0.013
Eigen_PC
Benign
0.041
FATHMM_MKL
Uncertain
0.77
D
LIST_S2
Benign
0.83
.;T;T;T;T;T;T;.;T
M_CAP
Pathogenic
0.62
D
MetaRNN
Pathogenic
0.76
D;D;D;D;D;D;D;D;D
MetaSVM
Uncertain
0.41
D
MutationAssessor
Benign
0.060
.;N;.;.;.;N;.;.;.
PhyloP100
1.5
PrimateAI
Benign
0.45
T
PROVEAN
Benign
-1.7
N;N;N;N;N;N;N;N;N
REVEL
Pathogenic
0.68
Sift
Benign
0.11
T;T;T;T;T;T;T;T;T
Sift4G
Benign
0.17
T;T;T;T;T;T;T;T;T
Polyphen
1.0
D;B;.;D;.;D;D;.;.
Vest4
0.64
MVP
0.86
MPC
0.92
ClinPred
0.67
D
GERP RS
3.9
Varity_R
0.15
gMVP
0.90
Mutation Taster
=0/100
disease causing

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.010
Details are displayed if max score is > 0.2

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

Publications

Other links and lift over

dbSNP: rs199473094; hg19: chr3-38648282; COSMIC: COSV61118761; API