rs777061524
Variant summary
Our verdict is Likely benign. The variant received -2 ACMG points: 0P and 2B. BP4_Moderate
The NM_001099404.2(SCN5A):c.1889C>T(p.Thr630Met) variant causes a missense, splice region change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000716 in 1,508,432 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 3/3 splice prediction tools predict no significant impact on normal splicing. 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. T630K) has been classified as Uncertain significance.
Frequency
Consequence
NM_001099404.2 missense, splice_region
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: Likely_benign. The variant received -2 ACMG points.
Transcripts
RefSeq
Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | MANE | Protein | UniProt |
---|---|---|---|---|---|---|---|---|
SCN5A | NM_001099404.2 | c.1889C>T | p.Thr630Met | missense_variant, splice_region_variant | Exon 12 of 28 | ENST00000413689.6 | NP_001092874.1 | |
SCN5A | NM_000335.5 | c.1889C>T | p.Thr630Met | missense_variant, splice_region_variant | Exon 12 of 28 | ENST00000423572.7 | NP_000326.2 |
Ensembl
Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | TSL | MANE | Protein | Appris | UniProt |
---|---|---|---|---|---|---|---|---|---|---|
SCN5A | ENST00000413689.6 | c.1889C>T | p.Thr630Met | missense_variant, splice_region_variant | Exon 12 of 28 | 5 | NM_001099404.2 | ENSP00000410257.1 | ||
SCN5A | ENST00000423572.7 | c.1889C>T | p.Thr630Met | missense_variant, splice_region_variant | Exon 12 of 28 | 1 | NM_000335.5 | ENSP00000398266.2 |
Frequencies
GnomAD3 genomes AF: 0.0000723 AC: 11AN: 152206Hom.: 0 Cov.: 32 show subpopulations
GnomAD2 exomes AF: 0.0000743 AC: 13AN: 175076 AF XY: 0.0000540 show subpopulations
GnomAD4 exome AF: 0.0000715 AC: 97AN: 1356226Hom.: 0 Cov.: 30 AF XY: 0.0000574 AC XY: 38AN XY: 662148 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.0000723 AC: 11AN: 152206Hom.: 0 Cov.: 32 AF XY: 0.0000807 AC XY: 6AN XY: 74352 show subpopulations
Age Distribution
ClinVar
Submissions by phenotype
not provided Uncertain:2
Reported in an individual with Brugada syndrome who harbored additional variants in the SCN5A and AKAP9 genes (PMID: 30847666); Identified in an individual with irritable bowel syndrome (IBS); however, no cardiac arrhythmia phenotype was reported (PMID: 24613995); Published in vitro functional studies suggest that this missense change may affect the channel function; however, it is unclear how these studies may translate to a pathogenic role in vivo (PMID: 24613995); In silico analysis indicates that this missense variant does not alter protein structure/function; This variant is associated with the following publications: (PMID: 25898860, 24613995, 30847666) -
This sequence change replaces threonine, which is neutral and polar, with methionine, which is neutral and non-polar, at codon 630 of the SCN5A protein (p.Thr630Met). This variant is present in population databases (rs777061524, gnomAD 0.01%). This missense change has been observed in individual(s) with Brugada syndrome (PMID: 30847666). ClinVar contains an entry for this variant (Variation ID: 201462). 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. Experimental studies are conflicting or provide insufficient evidence to determine the effect of this variant on SCN5A function (PMID: 24613995). 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. -
not specified Uncertain:1
Variant summary: SCN5A c.1889C>T (p.Thr630Met) results in a non-conservative amino acid change located in the Voltage-gated Na+ ion channel, cytoplasmic domain (IPR024583) of the encoded protein sequence. Three of five in-silico tools predict a benign effect of the variant on protein function. Consensus agreement among computation tools predict no significant impact on normal splicing. However, these predictions have yet to be confirmed by functional studies. The variant allele was found at a frequency of 7.4e-05 in 175076 control chromosomes. This frequency is not significantly higher than estimated for a pathogenic variant in SCN5A causing Brugada Syndrome (7.4e-05 vs 0.00017), allowing no conclusion about variant significance. c.1889C>T has been reported in the literature in at least two individuals affected with Brugada Syndrome and one with fever-induced Brugada Syndrome, however two of these individuals harbored other potentially causative variants in SCN5A (e.g. van Lint_2019, Chen_2023). This variant has also been reported in an indvidual affected with irritable bowel syndrome, but no cardiac phenotype was reported (Beyder_2014). These reports do not provide unequivocal conclusions about association of the variant with Brugada Syndrome. At least one publication reports experimental evidence evaluating an impact on protein function (e.g. Beyder_2014). In voltage clamp analysis the variant exhibited faster inactivation compared to the WT protein, however the clinical significance of this finding does not allow for convincing conclusions about the variant effect. The following publications have been ascertained in the context of this evaluation (PMID: 30847666, 24613995, 36516610). ClinVar contains an entry for this variant (Variation ID: 201462). Based on the evidence outlined above, the variant was classified as uncertain significance. -
Brugada syndrome 1 Uncertain:1
We classified this variant using data from the calibrated functional assay 'ParSE-seq' (PMID: 37732247), population data, and in silico data within the ACMG v3 framework (PMID: 25741868)The SCN5A variant, 3-38603713-G-A was evaluated for association with the loss-of-function condition Brugada Syndrome.This Variant had an AF of 0.0000723 in gnomAD v3The in silico predictor SpliceAI scored the variant as 0.11; normal <0.2, likely damaging >0.5.Using the functional RNA-splicing assay, ParSE-seq, the variant was evaluated to have an indeterminate impact on splicing following the Brnich et al. calibration framework (PMID: 31892348). In aggregate, we therefore classify this variant as VUS using these collective data. -
SUDDEN INFANT DEATH SYNDROME;C1832680:Dilated cardiomyopathy 1E;C1837845:Sick sinus syndrome 1;C1859062:Long QT syndrome 3;C1879286:Progressive familial heart block, type 1A;C2751898:Ventricular fibrillation, paroxysmal familial, type 1;C3151464:Atrial fibrillation, familial, 10;C4551804:Brugada syndrome 1 Uncertain:1
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Cardiovascular phenotype Uncertain:1
The p.T630M variant (also known as c.1889C>T), located in coding exon 11 of the SCN5A gene, results from a C to T substitution at nucleotide position 1889. The threonine at codon 630 is replaced by methionine, an amino acid with similar properties. This variant was reported in an individual from a cohort of patients with irritable bowel syndrome being assessed for variants in SCN5A, and via an in vitro voltage clamp analysis, resulted in loss of function through faster inactivation of the Nav1.5 channel compared to wild type (Beyder A et al. Gastroenterology 2014;146(7):1659-68). This variant was also detected in a cardiomyopathy/arrhythmia genetic testing cohort; however, clinical details were limited, and additional cardiac variants were detected in some cases (van Lint FHM et al. Neth Heart J, 2019 Jun;27:304-309). This alteration has also been reported in association with Brugada syndrome (Chen GX et al. EBioMedicine, 2023 Jan;87:104388). This amino acid position is highly conserved in available vertebrate species. In addition, the in silico prediction for this alteration is inconclusive. Since supporting evidence is limited at this time, the clinical significance of this variant remains unclear. -
Cardiac arrhythmia Uncertain:1
This missense variant replaces threonine with methionine at codon 630 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). A functional study has shown that this variant alters inactivation kinetics of the sodium channel (PMID: 24613995). This variant has been reported in an individual affected with Brugada syndrome (PMID: 30847666). This variant has been identified in 14/206444 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. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at