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
Consequence
NM_001099404.2 missense
Scores
Clinical Significance
Conservation
Publications
- Brugada syndromeInheritance: AD Classification: DEFINITIVE, SUPPORTIVE Submitted by: ClinGen, Orphanet
- Brugada syndrome 1Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Ambry Genetics, Laboratory for Molecular Medicine, G2P, Genomics England PanelApp, Labcorp Genetics (formerly Invitae)
- dilated cardiomyopathyInheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
- dilated cardiomyopathy 1EInheritance: AD Classification: DEFINITIVE, STRONG Submitted by: G2P, Labcorp Genetics (formerly Invitae), Ambry Genetics
- familial long QT syndromeInheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
- long QT syndrome 3Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae), G2P
- sick sinus syndrome 1Inheritance: AD, AR Classification: STRONG, LIMITED Submitted by: Labcorp Genetics (formerly Invitae)
- progressive familial heart block, type 1AInheritance: SD, AD Classification: STRONG, MODERATE Submitted by: Ambry Genetics, Genomics England PanelApp
- atrial standstillInheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
- familial atrial fibrillationInheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
- familial isolated dilated cardiomyopathyInheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
- familial sick sinus syndromeInheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
- paroxysmal familial ventricular fibrillationInheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
- progressive familial heart blockInheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
- arrhythmogenic right ventricular cardiomyopathyInheritance: AD Classification: LIMITED Submitted by: ClinGen
- catecholaminergic polymorphic ventricular tachycardiaInheritance: AD Classification: NO_KNOWN Submitted by: ClinGen
- short QT syndromeInheritance: AD Classification: NO_KNOWN Submitted by: ClinGen
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ACMG classification
Our verdict: Uncertain_significance. The variant received 3 ACMG points.
Transcripts
RefSeq
Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | MANE | Protein | UniProt |
---|---|---|---|---|---|---|---|---|
SCN5A | NM_001099404.2 | c.1018C>T | p.Arg340Trp | missense_variant | Exon 9 of 28 | ENST00000413689.6 | NP_001092874.1 | |
SCN5A | NM_000335.5 | c.1018C>T | p.Arg340Trp | missense_variant | Exon 9 of 28 | ENST00000423572.7 | NP_000326.2 |
Ensembl
Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | TSL | MANE | Protein | Appris | UniProt |
---|---|---|---|---|---|---|---|---|---|---|
SCN5A | ENST00000413689.6 | c.1018C>T | p.Arg340Trp | missense_variant | Exon 9 of 28 | 5 | NM_001099404.2 | ENSP00000410257.1 | ||
SCN5A | ENST00000423572.7 | c.1018C>T | p.Arg340Trp | missense_variant | Exon 9 of 28 | 1 | NM_000335.5 | ENSP00000398266.2 |
Frequencies
GnomAD3 genomes AF: 0.00000657 AC: 1AN: 152260Hom.: 0 Cov.: 33 show subpopulations
GnomAD2 exomes AF: 0.00000402 AC: 1AN: 248454 AF XY: 0.00 show subpopulations
GnomAD4 exome AF: 0.0000123 AC: 18AN: 1461204Hom.: 0 Cov.: 31 AF XY: 0.00000963 AC XY: 7AN XY: 726852 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.00000657 AC: 1AN: 152260Hom.: 0 Cov.: 33 AF XY: 0.0000134 AC XY: 1AN XY: 74384 show subpopulations
Age Distribution
ClinVar
Submissions by phenotype
not provided Uncertain:3
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) -
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. -
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not specified Uncertain:1
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
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
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
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:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at