chr3-38633204-C-T

Variant names:

• chr3-38633204-C-T
• rs867508345
• NM_001099404.2:c.104G>A

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 5P and 1B. PM1 PM2 PP2 BP4

The NM_000335.5(SCN5A):​c.104G>A​(p.Gly35Asp) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,124 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 14/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: SCN5A NM_000335.5 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 1.97

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 4 ACMG points.

• PM1: In a topological_domain Cytoplasmic (size 130) in uniprot entity SCN5A_HUMAN there are 19 pathogenic changes around while only 2 benign (90%) 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.
• BP4: Computational evidence support a benign effect (MetaRNN=0.30917656).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
SCN5A	NM_001099404.2	c.104G>A	p.Gly35Asp	missense_variant	Exon 2 of 28	ENST00000413689.6	NP_001092874.1
SCN5A	NM_000335.5	c.104G>A	p.Gly35Asp	missense_variant	Exon 2 of 28	ENST00000423572.7	NP_000326.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
SCN5A	ENST00000413689.6	c.104G>A	p.Gly35Asp	missense_variant	Exon 2 of 28	5	NM_001099404.2	ENSP00000410257.1
SCN5A	ENST00000423572.7	c.104G>A	p.Gly35Asp	missense_variant	Exon 2 of 28	1	NM_000335.5	ENSP00000398266.2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461124 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 726850

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: 8.99e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Brugada syndrome Uncertain:1

Jun 08, 2018

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces glycine with aspartic acid at codon 35 of the SCN5A protein (p.Gly35Asp). The glycine residue is moderately conserved and there is a moderate physicochemical difference between glycine and aspartic acid. This variant is not present in population databases (ExAC no frequency). This variant has not been reported in the literature in individuals with SCN5A-related disease. 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. 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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.084
CardioboostCm	Benign	0.012
BayesDel_addAF	Benign	-0.022	T
BayesDel_noAF	Benign	-0.27
CADD	Benign	14
DANN	Uncertain	0.98
DEOGEN2	Benign	0.37	.;.;.;.;.;T;.;.;.;T;T
Eigen	Benign	-0.44
Eigen_PC	Benign	-0.30
FATHMM_MKL	Benign	0.63	D
LIST_S2	Uncertain	0.89	.;D;D;D;D;D;D;.;D;D;D
M_CAP	Pathogenic	0.31	D
MetaRNN	Benign	0.31	T;T;T;T;T;T;T;T;T;T;T
MetaSVM	Benign	-0.66	T
MutationAssessor	Benign	0.46	.;N;.;.;.;N;.;.;.;.;.
PrimateAI	Benign	0.37	T
PROVEAN	Benign	0.15	N;N;N;N;N;N;N;N;N;.;N
REVEL	Uncertain	0.31
Sift	Benign	0.13	T;T;T;T;D;T;T;D;D;.;T
Sift4G	Benign	0.18	T;T;T;T;T;T;T;T;T;T;.
Polyphen		0.043	B;B;.;B;.;B;B;.;.;.;.
Vest4		0.32
MutPred		0.31		Loss of MoRF binding (P = 0.0406);Loss of MoRF binding (P = 0.0406);Loss of MoRF binding (P = 0.0406);Loss of MoRF binding (P = 0.0406);Loss of MoRF binding (P = 0.0406);Loss of MoRF binding (P = 0.0406);Loss of MoRF binding (P = 0.0406);Loss of MoRF binding (P = 0.0406);Loss of MoRF binding (P = 0.0406);Loss of MoRF binding (P = 0.0406);Loss of MoRF binding (P = 0.0406);
MVP		0.60
MPC		0.79
ClinPred		0.17	T
GERP RS		4.5
Varity_R		0.039
gMVP		0.46

Splicing

Name	Calibrated prediction	Score	Prediction
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: rs867508345; hg19: chr3-38674695;