rs199473105

Variant summary

Our verdict is Likely pathogenic. The variant received 8 ACMG points: 8P and 0B. PM1PM2PP3_Strong

The NM_001099404.2(SCN5A):​c.1190T>C​(p.Ile397Thr) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000248 in 1,613,864 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. I397V) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)
Exomes 𝑓: 0.0000021 ( 0 hom. )

Consequence

SCN5A
NM_001099404.2 missense

Scores

16
4
1

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:4O:1

Conservation

PhyloP100: 9.32

Publications

5 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: Likely_pathogenic. The variant received 8 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, 15 uncertain in NM_001099404.2
PM2
Very rare variant in population databases, with high coverage;
PP3
MetaRNN computational evidence supports a deleterious effect, 0.981

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
SCN5ANM_001099404.2 linkc.1190T>C p.Ile397Thr missense_variant Exon 10 of 28 ENST00000413689.6 NP_001092874.1 Q14524H9KVD2
SCN5ANM_000335.5 linkc.1190T>C p.Ile397Thr missense_variant Exon 10 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.1190T>C p.Ile397Thr missense_variant Exon 10 of 28 5 NM_001099404.2 ENSP00000410257.1 H9KVD2
SCN5AENST00000423572.7 linkc.1190T>C p.Ile397Thr missense_variant Exon 10 of 28 1 NM_000335.5 ENSP00000398266.2 Q14524-2

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152206
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.00
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:
0.0000147
Gnomad OTH
AF:
0.00
GnomAD4 exome
AF:
0.00000205
AC:
3
AN:
1461658
Hom.:
0
Cov.:
31
AF XY:
0.00000138
AC XY:
1
AN XY:
727120
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33480
American (AMR)
AF:
0.00
AC:
0
AN:
44722
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39700
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86256
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53374
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.00000270
AC:
3
AN:
1111848
Other (OTH)
AF:
0.00
AC:
0
AN:
60374
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.458
Heterozygous variant carriers
0
1
1
2
2
3
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
GnomAD4 genome
AF:
0.00000657
AC:
1
AN:
152206
Hom.:
0
Cov.:
32
AF XY:
0.0000134
AC XY:
1
AN XY:
74368
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41456
American (AMR)
AF:
0.00
AC:
0
AN:
15290
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3468
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5192
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4828
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10620
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
68038
Other (OTH)
AF:
0.00
AC:
0
AN:
2086
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.525
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
Alfa
AF:
0.0000294
Hom.:
0
Bravo
AF:
0.00000378

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:4Other:1
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not provided Uncertain:2
Jan 06, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces isoleucine, which is neutral and non-polar, with threonine, which is neutral and polar, at codon 397 of the SCN5A protein (p.Ile397Thr). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individual(s) with referral for long QT syndrome testing (PMID: 19716085). ClinVar contains an entry for this variant (Variation ID: 67644). 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 disruptive. 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. -

Dec 01, 2023
GeneDx
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Observed in an individual referred for LQTS genetic testing (PMID: 19716085); Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; This variant is associated with the following publications: (PMID: 34803699, 19716085, 36136372) -

not specified Uncertain:1
Sep 26, 2021
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.1190T>C (p.Ile397Thr) results in a non-conservative amino acid change located in the Ion transport domain (IPR005821) of the encoded protein sequence. Five of five in-silico tools predict a damaging effect of the variant on protein function. The variant was absent in 249224 control chromosomes. The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. c.1190T>C has been reported in the literature in settings of multigene panel testing in at-least one individual referred for long QT syndrome (LQTS) (example, Kapplinger_2009). These report(s) do not provide unequivocal conclusions about association of the variant with Arrhythmia/LQTS. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. Two clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. One laboratory classified the variant as likely pathogenic, and one laboratory classified the variant as uncertain significance citing overlapping evidence utilized in the context of this evaluation. Based on the evidence outlined above, the variant was classified as uncertain significance. -

Cardiac arrhythmia Uncertain:1
Aug 06, 2024
All of Us Research Program, National Institutes of Health
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This missense variant replaces isoleucine with threonine at codon 397 of the SCN5A protein. Computational prediction suggests that this variant may have deleterious impact on protein structure and function (internally defined REVEL score threshold >= 0.7, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has been reported in one individual affected with long QT syndrome (PMID: 19716085). This variant has not been identified 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). 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
0.96
CardioboostArm
Uncertain
0.83
CardioboostCm
Uncertain
0.90
BayesDel_addAF
Pathogenic
0.57
D
BayesDel_noAF
Pathogenic
0.58
CADD
Pathogenic
26
DANN
Uncertain
1.0
DEOGEN2
Pathogenic
0.97
.;.;.;.;.;D;.;.;.
Eigen
Pathogenic
1.0
Eigen_PC
Pathogenic
0.93
FATHMM_MKL
Pathogenic
0.99
D
LIST_S2
Pathogenic
0.98
.;D;D;D;D;D;D;.;D
M_CAP
Pathogenic
0.85
D
MetaRNN
Pathogenic
0.98
D;D;D;D;D;D;D;D;D
MetaSVM
Pathogenic
1.1
D
MutationAssessor
Pathogenic
3.2
.;M;.;.;.;M;.;.;.
PhyloP100
9.3
PrimateAI
Pathogenic
0.90
D
PROVEAN
Pathogenic
-4.9
D;D;D;D;D;D;D;D;D
REVEL
Pathogenic
0.99
Sift
Pathogenic
0.0
D;D;D;D;D;D;D;D;D
Sift4G
Uncertain
0.019
D;D;D;D;D;D;D;D;D
Polyphen
1.0
D;D;.;D;.;D;D;.;.
Vest4
0.94
MutPred
0.87
Loss of stability (P = 0.0162);Loss of stability (P = 0.0162);Loss of stability (P = 0.0162);Loss of stability (P = 0.0162);Loss of stability (P = 0.0162);Loss of stability (P = 0.0162);Loss of stability (P = 0.0162);Loss of stability (P = 0.0162);Loss of stability (P = 0.0162);
MVP
0.99
MPC
1.3
ClinPred
1.0
D
GERP RS
5.5
Varity_R
0.88
gMVP
0.99
Mutation Taster
=0/100
disease causing (ClinVar)

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

Other links and lift over

dbSNP: rs199473105; hg19: chr3-38647590; API