3-38550424-G-C

Variant names:

• chr3-38550424-G-C
• rs771243543
• NM_001099404.2:c.5948C>G

Variant summary

Our verdict is Uncertain significance. Variant got 1 ACMG points: 3P and 2B. PM2 PP2 BP4_Moderate

The NM_000335.5(SCN5A):​c.5945C>G​(p.Ala1982Gly) variant causes a missense change. The variant allele was found at a frequency of 0.0000292 in 1,437,658 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 13/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Synonymous variant affecting the same amino acid position (i.e. A1982A) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.000029 (0 hom.)
• Consequence: SCN5A NM_000335.5 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 6.61

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 1 ACMG points.

• 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=0.1006856).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
SCN5A	NM_001099404.2	c.5948C>G	p.Ala1983Gly	missense_variant	Exon 28 of 28	ENST00000413689.6	NP_001092874.1
SCN5A	NM_000335.5	c.5945C>G	p.Ala1982Gly	missense_variant	Exon 28 of 28	ENST00000423572.7	NP_000326.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
SCN5A	ENST00000413689.6	c.5948C>G	p.Ala1983Gly	missense_variant	Exon 28 of 28	5	NM_001099404.2	ENSP00000410257.1
SCN5A	ENST00000423572.7	c.5945C>G	p.Ala1982Gly	missense_variant	Exon 28 of 28	1	NM_000335.5	ENSP00000398266.2

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD3 exomes AF: 0.00000850 AC: 2 AN: 235222 Hom.: 0 AF XY: 0.00000790 AC XY: 1 AN XY: 126538

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000187

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000292 AC: 42 AN: 1437658 Hom.: 0 Cov.: 31 AF XY: 0.0000281 AC XY: 20 AN XY: 711112

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: 0.0000374

Gnomad4 OTH exome AF: 0.0000169

GnomAD4 genome Cov.: 33

Alfa AF: 0.0000712 Hom.: 0

Bravo AF: 0.0000113

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Uncertain:1

Dec 02, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces alanine, which is neutral and non-polar, with glycine, which is neutral and non-polar, at codon 1983 of the SCN5A protein (p.Ala1983Gly). This variant is present in population databases (no rsID available, gnomAD 0.002%). This missense change has been observed in individual(s) with clinical features of SCN5A-related conditions (internal data). ClinVar contains an entry for this variant (Variation ID: 463356). An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant is likely to be disruptive. 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. -

Cardiac arrhythmia Uncertain:1

Apr 24, 2023

Color Diagnostics, LLC DBA Color Health

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This missense variant replaces alanine with glycine at codon 1983 of 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 3/266622 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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.11
CardioboostCm	Benign	0.0082
BayesDel_addAF	Uncertain	0.058	T
BayesDel_noAF	Benign	-0.13
CADD	Benign	23
DANN	Uncertain	0.99
DEOGEN2	Benign	0.38	.;.;.;.;.;T;.;.;.
Eigen	Benign	-0.083
Eigen_PC	Benign	0.14
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Benign	0.78	.;T;T;T;T;T;T;.;T
M_CAP	Benign	0.077	D
MetaRNN	Benign	0.10	T;T;T;T;T;T;T;T;T
MetaSVM	Uncertain	0.095	D
MutationAssessor	Benign	-0.69	.;.;.;.;.;N;.;.;.
PrimateAI	Uncertain	0.60	T
PROVEAN	Benign	-0.16	N;N;N;N;N;N;N;N;N
REVEL	Benign	0.23
Sift	Benign	0.43	T;T;T;T;T;T;T;T;T
Sift4G	Benign	0.79	T;T;T;T;T;T;T;T;T
Polyphen		0.0080	B;B;.;B;.;B;B;.;.
Vest4		0.086
MVP		0.58
MPC		1.4
ClinPred		0.47	T
GERP RS		5.0
Varity_R		0.12
gMVP		0.25

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: rs771243543; hg19: chr3-38591915;