3-38576780-G-C

Position:

• chr3-38576780-G-C

Variant summary

Our verdict is Uncertain significance. Variant got 5 ACMG points: 7P and 2B. PM1 PM2 PM5 PP2 BP4_Moderate

The NM_000335.5(SCN5A):​c.3389C>G​(p.Thr1130Ser) variant causes a missense, splice region change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000187 in 1,608,210 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 16/24 in silico tools predict 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. T1130N) has been classified as Likely pathogenic.

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 33)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: SCN5A NM_000335.5 missense, splice_region
• Scores: Splicing: ADA: 0.00002631
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:4
• Conservation: PhyloP100: -0.191

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 (HGNC:):

ACMG classification

Verdict is Uncertain_significance. Variant got 5 ACMG points.

• PM1: In a topological_domain Cytoplasmic (size 267) in uniprot entity SCN5A_HUMAN there are 26 pathogenic changes around while only 11 benign (70%) in NM_000335.5
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr3-38576780-G-T is described in Lovd as [Likely_pathogenic].
• PP2: Missense variant in gene, where missense usually causes diseases (based on misZ statistic), SCN5A. . Gene score misZ 2.7504 (greater than the threshold 3.09). Trascript score misZ 4.8279 (greater than threshold 3.09). GenCC has associacion of gene with progressive familial heart block, type 1A, Brugada syndrome, familial sick sinus syndrome, short QT syndrome, paroxysmal familial ventricular fibrillation, progressive familial heart block, long QT syndrome 3, familial atrial fibrillation, catecholaminergic polymorphic ventricular tachycardia, dilated cardiomyopathy, dilated cardiomyopathy 1E, arrhythmogenic right ventricular cardiomyopathy, Brugada syndrome 1, atrial standstill, familial isolated dilated cardiomyopathy, familial long QT syndrome, sick sinus syndrome 1.
• BP4: Computational evidence support a benign effect (MetaRNN=0.10551569).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
SCN5A	NM_001099404.2	c.3392C>G	p.Thr1131Ser	missense_variant, splice_region_variant	19/28	ENST00000413689.6	NP_001092874.1
SCN5A	NM_000335.5	c.3389C>G	p.Thr1130Ser	missense_variant, splice_region_variant	19/28	ENST00000423572.7	NP_000326.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
SCN5A	ENST00000413689.6	c.3392C>G	p.Thr1131Ser	missense_variant, splice_region_variant	19/28	5	NM_001099404.2	ENSP00000410257.1
SCN5A	ENST00000423572.7	c.3389C>G	p.Thr1130Ser	missense_variant, splice_region_variant	19/28	1	NM_000335.5	ENSP00000398266.2

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152266 Hom.: 0 Cov.: 33

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: 0.00000137 AC: 2 AN: 1455944 Hom.: 0 Cov.: 30 AF XY: 0.00000276 AC XY: 2 AN XY: 723520

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000180

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152266 Hom.: 0 Cov.: 33 AF XY: 0.0000134 AC XY: 1 AN XY: 74396

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000147

Gnomad4 OTH AF: 0.00

Bravo AF: 0.00000378

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:4

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Cardiac arrhythmia Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	All of Us Research Program, National Institutes of Health	Sep 17, 2023	This variant is located in the SCN5A protein. Computational prediction suggests that this variant may not impact protein structure and function (internally defined REVEL score threshold <= 0.5, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has not been reported in individuals affected with SCN5A-related disorders in the literature. This variant has been identified in 1/31400 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. -
Uncertain significance, criteria provided, single submitter	clinical testing	Color Diagnostics, LLC DBA Color Health	Sep 01, 2023	This variant is located in the SCN5A protein. Computational prediction suggests that this variant may not impact protein structure and function (internally defined REVEL score threshold <= 0.5, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has not been reported in individuals affected with SCN5A-related disorders in the literature. This variant has been identified in 1/31400 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. -

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Oct 25, 2017

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. Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be tolerated, but these predictions have not been confirmed by published functional studies and their clinical significance is uncertain. This variant identified in the SCN5A gene is located in the interdomain linker DII/DIII region of the resulting protein (PMID: 25348405). For more information about the location of this variant, please visit www.invitae.com/SCN5A-topology. It is unclear how this variant impacts the function of this protein. This variant has not been reported in the literature in individuals with SCN5A-related disease. This variant is not present in population databases (ExAC no frequency). This sequence change replaces threonine with serine at codon 1131 of the SCN5A protein (p.Thr1131Ser). The threonine residue is weakly conserved and there is a small physicochemical difference between threonine and serine. -

Cardiovascular phenotype Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Jan 31, 2022

The p.T1131S variant (also known as c.3392C>G), located in coding exon 18 of the SCN5A gene, results from a C to G substitution at nucleotide position 3392. The threonine at codon 1131 is replaced by serine, an amino acid with similar properties. This variant has been detected in an individual from a control cohort; however, clinical details were limited (Kapplinger JD et al. Circ Cardiovasc Genet, 2015 Aug;8:582-95).This amino acid position is not well 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 alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.076
CardioboostCm	Benign	0.0045
BayesDel_addAF	Uncertain	0.054	T
BayesDel_noAF	Benign	-0.16
CADD	Benign	6.5
DANN	Benign	0.61
DEOGEN2	Benign	0.38	.;.;.;.;.;T;.;.;.
Eigen	Benign	-1.3
Eigen_PC	Benign	-1.3
FATHMM_MKL	Benign	0.054	N
LIST_S2	Benign	0.47	.;T;T;T;T;T;T;.;T
M_CAP	Uncertain	0.26	D
MetaRNN	Benign	0.11	T;T;T;T;T;T;T;T;T
MetaSVM	Uncertain	-0.22	T
MutationAssessor	Benign	0.20	.;.;.;.;.;N;.;.;.
PrimateAI	Benign	0.36	T
PROVEAN	Benign	-0.50	N;N;N;N;N;N;N;N;N
REVEL	Uncertain	0.38
Sift	Benign	0.71	T;T;T;T;T;T;T;T;T
Sift4G	Benign	0.70	T;T;T;T;T;T;T;T;T
Polyphen		0.0030	B;B;.;B;.;B;B;.;.
Vest4		0.14
MutPred		0.49		Loss of glycosylation at T1131 (P = 0.1265);.;Loss of glycosylation at T1131 (P = 0.1265);Loss of glycosylation at T1131 (P = 0.1265);.;Loss of glycosylation at T1131 (P = 0.1265);.;.;.;
MVP		0.83
MPC		0.031
ClinPred		0.053	T
GERP RS		0.16
Varity_R		0.025
gMVP		0.26

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Benign	0.000026
dbscSNV1_RF	Benign	0.028
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

LitVar

Other links and lift over

dbSNP: rs199473197; hg19: chr3-38618271;