3-38579439-C-G

Variant names:

• chr3-38579439-C-G
• rs759924541
• NM_001099404.2:c.3285G>C

Variant summary

Our verdict is Uncertain significance. Variant got 5 ACMG points: 5P and 0B. PM1 PM2 PP2

The NM_000335.5(SCN5A):​c.3282G>C​(p.Trp1094Cys) 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 (★).

• Frequency: Genomes: not found (cov: 33)
• Consequence: SCN5A NM_000335.5 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 2.08

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]

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
• PP2: Missense variant in the SCN5A gene, where missense mutations are typically associated with disease (based on misZ statistic). The gene has 99 curated pathogenic missense variants (we use a threshold of 10). The gene has 60 curated benign missense variants. Gene score misZ: 2.7504 (below the threshold of 3.09). Trascript score misZ: 4.8279 (above the threshold of 3.09). GenCC associations: The gene is linked to 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 rank	MANE	Protein	UniProt
SCN5A	NM_001099404.2	c.3285G>C	p.Trp1095Cys	missense_variant	Exon 18 of 28	ENST00000413689.6	NP_001092874.1
SCN5A	NM_000335.5	c.3282G>C	p.Trp1094Cys	missense_variant	Exon 18 of 28	ENST00000423572.7	NP_000326.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
SCN5A	ENST00000413689.6	c.3285G>C	p.Trp1095Cys	missense_variant	Exon 18 of 28	5	NM_001099404.2	ENSP00000410257.1
SCN5A	ENST00000423572.7	c.3282G>C	p.Trp1094Cys	missense_variant	Exon 18 of 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:1

Revision: criteria provided, single submitter

Submissions by phenotype

Cardiovascular phenotype Uncertain:1

Jun 03, 2016

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.W1095C variant (also known as c.3285G>C), located in coding exon 17 of the SCN5A gene, results from a G to C substitution at nucleotide position 3285. The tryptophan at codon 1095 is replaced by cysteine, an amino acid with highly dissimilar properties. This variant was not reported in population based cohorts in the following databases: Database of Single Nucleotide Polymorphisms (dbSNP), Exome Aggregation Consortium (ExAC), NHLBI Exome Sequencing Project (ESP), and 1000 Genomes Project. In the ESP, this variant was not observed in 6271 samples (12542 alleles) with coverage at this position. This amino acid position is well conserved on limited sequence alignment. 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	0.28
CardioboostCm	Benign	0.00091
BayesDel_addAF	Pathogenic	0.25	D
BayesDel_noAF	Uncertain	0.13
CADD	Uncertain	23
DANN	Benign	0.95
DEOGEN2	Uncertain	0.49	.;.;.;.;T;.
Eigen	Benign	0.076
Eigen_PC	Benign	0.13
FATHMM_MKL	Uncertain	0.84	D
LIST_S2	Uncertain	0.92	.;D;D;D;D;D
M_CAP	Uncertain	0.16	D
MetaRNN	Uncertain	0.48	T;T;T;T;T;T
MetaSVM	Uncertain	0.43	D
MutationAssessor	Benign	1.7	.;.;.;.;L;.
PROVEAN	Benign	-0.88	N;N;N;N;N;N
REVEL	Uncertain	0.61
Sift	Benign	0.17	T;T;T;T;T;T
Sift4G	Benign	0.18	T;T;T;T;T;T
Polyphen		0.65	P;P;.;P;P;P
Vest4		0.55
MutPred		0.44		Gain of loop (P = 0.0097);.;Gain of loop (P = 0.0097);Gain of loop (P = 0.0097);Gain of loop (P = 0.0097);.;
MVP		0.46
MPC		0.15
ClinPred		0.76	D
GERP RS		3.4
Varity_R		0.21
gMVP		0.75

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: rs759924541; hg19: chr3-38620930;