rs199473562

Positions:

• chr3-38609836-G-A
• chr3-38609836-G-C

Variant summary

Our verdict is Uncertain significance. Variant got 5 ACMG points: 5P and 0B. PM2 PM5 PP2

The NM_000335.5(SCN5A):​c.832C>T​(p.His278Tyr) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. 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. H278D) has been classified as Pathogenic.

• Frequency: Genomes: not found (cov: 33)
• Consequence: SCN5A NM_000335.5 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 3.36

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.

• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr3-38609836-G-C is described in Lovd as [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.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
SCN5A	NM_001099404.2	c.832C>T	p.His278Tyr	missense_variant	7/28	ENST00000413689.6	NP_001092874.1
SCN5A	NM_000335.5	c.832C>T	p.His278Tyr	missense_variant	7/28	ENST00000423572.7	NP_000326.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
SCN5A	ENST00000413689.6	c.832C>T	p.His278Tyr	missense_variant	7/28	5	NM_001099404.2	ENSP00000410257.1
SCN5A	ENST00000423572.7	c.832C>T	p.His278Tyr	missense_variant	7/28	1	NM_000335.5	ENSP00000398266.2

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 33

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Brugada syndrome 1 Uncertain:1

Uncertain significance, criteria provided, single submitter

in vitro;research

Roden Lab, Vanderbilt University Medical Center

-

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, 3-38609836-G-A was evaluated for association with the loss-of-function condition Brugada Syndrome.This Variant had an AF of 0 in gnomAD v3The in silico predictor SpliceAI scored the variant as 0.3238; normal <0.2, likely damaging >0.5.Using the functional RNA-splicing assay, ParSE-seq, the variant was evaluated to have a strong negative impact on splicing (PS3_strong) following the Brnich et al. calibration framework (PMID: 31892348). In aggregate, we therefore classify this variant as VUS using these collective data. -

Cardiac arrhythmia Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Color Diagnostics, LLC DBA Color Health

Jan 05, 2021

This missense variant replaces histidine with tyrosine at codon 278 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 not been reported in individuals affected with cardiovascular disorders in the literature. 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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.28
CardioboostCm	Benign	0.063
BayesDel_addAF	Pathogenic	0.26	D
BayesDel_noAF	Pathogenic	0.14
CADD	Uncertain	24
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.89	.;.;.;.;.;D;.;.;.
Eigen	Uncertain	0.38
Eigen_PC	Uncertain	0.46
FATHMM_MKL	Uncertain	0.95	D
LIST_S2	Benign	0.76	.;T;T;T;T;T;T;.;T
M_CAP	Pathogenic	0.30	D
MetaRNN	Uncertain	0.61	D;D;D;D;D;D;D;D;D
MetaSVM	Pathogenic	0.98	D
MutationAssessor	Benign	0.60	.;N;.;.;.;N;.;.;.
PrimateAI	Uncertain	0.71	T
PROVEAN	Uncertain	-3.4	D;D;D;D;D;D;D;D;D
REVEL	Pathogenic	0.69
Sift	Benign	0.037	D;D;D;D;D;D;D;D;D
Sift4G	Uncertain	0.041	D;D;D;D;D;D;D;D;D
Polyphen		0.96	D;B;.;D;.;D;D;.;.
Vest4		0.61
MutPred		0.58		Loss of sheet (P = 0.0228);Loss of sheet (P = 0.0228);Loss of sheet (P = 0.0228);Loss of sheet (P = 0.0228);Loss of sheet (P = 0.0228);Loss of sheet (P = 0.0228);Loss of sheet (P = 0.0228);Loss of sheet (P = 0.0228);Loss of sheet (P = 0.0228);
MVP		0.60
MPC		1.1
ClinPred		0.97	D
GERP RS		4.4
Varity_R		0.52
gMVP		0.97

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.31		Details are displayed if max score is > 0.2
DS_DG_spliceai		0.31		Position offset: 2

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

Publications

No publications associated with this variant yet.

Other links and lift over

hg19: chr3-38651327;