3-38606751-G-C

Position:

• chr3-38606751-G-C

Variant summary

Our verdict is Likely pathogenic. Variant got 9 ACMG points: 9P and 0B. PM2 PM5 PP2 PP3_Strong

The NM_000335.5(SCN5A):​c.1058C>G​(p.Thr353Ser) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. 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. T353I) 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: 10.0

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 Likely_pathogenic. Variant got 9 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr3-38606751-G-A 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.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.942

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
SCN5A	NM_001099404.2	c.1058C>G	p.Thr353Ser	missense_variant	9/28	ENST00000413689.6	NP_001092874.1
SCN5A	NM_000335.5	c.1058C>G	p.Thr353Ser	missense_variant	9/28	ENST00000423572.7	NP_000326.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
SCN5A	ENST00000413689.6	c.1058C>G	p.Thr353Ser	missense_variant	9/28	5	NM_001099404.2	ENSP00000410257.1
SCN5A	ENST00000423572.7	c.1058C>G	p.Thr353Ser	missense_variant	9/28	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

clinical testing

Center for Genomic Medicine, King Faisal Specialist Hospital and Research Center

Apr 04, 2024

- -

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jul 12, 2022

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. This variant disrupts the p.Thr353 amino acid residue in SCN5A. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 17198989). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. 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 disruptive. ClinVar contains an entry for this variant (Variation ID: 1041885). This variant has not been reported in the literature in individuals affected with SCN5A-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces threonine, which is neutral and polar, with serine, which is neutral and polar, at codon 353 of the SCN5A protein (p.Thr353Ser). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.90
CardioboostCm	Pathogenic	0.96
BayesDel_addAF	Pathogenic	0.40	D
BayesDel_noAF	Pathogenic	0.34
CADD	Uncertain	26
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.97	.;.;.;.;.;D;.;.;.
Eigen	Pathogenic	0.93
Eigen_PC	Pathogenic	0.85
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Pathogenic	1.0	.;D;D;D;D;D;D;.;D
M_CAP	Pathogenic	0.86	D
MetaRNN	Pathogenic	0.94	D;D;D;D;D;D;D;D;D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Pathogenic	3.1	.;M;.;.;.;M;.;.;.
PrimateAI	Uncertain	0.69	T
PROVEAN	Uncertain	-3.9	D;D;D;D;D;D;D;D;D
REVEL	Pathogenic	0.94
Sift	Pathogenic	0.0	D;D;D;D;D;D;D;D;D
Sift4G	Uncertain	0.013	D;D;D;D;D;D;D;D;D
Polyphen		1.0	D;D;.;D;.;D;D;.;.
Vest4		0.89
MutPred		0.70		Gain of disorder (P = 0.0289);Gain of disorder (P = 0.0289);Gain of disorder (P = 0.0289);Gain of disorder (P = 0.0289);Gain of disorder (P = 0.0289);Gain of disorder (P = 0.0289);Gain of disorder (P = 0.0289);Gain of disorder (P = 0.0289);Gain of disorder (P = 0.0289);
MVP		0.95
MPC		1.1
ClinPred		1.0	D
GERP RS		4.7
Varity_R		0.89
gMVP		0.91

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

LitVar

Other links and lift over

dbSNP: rs199473096; hg19: chr3-38648242;