3-38603713-G-C

Variant names:

• chr3-38603713-G-C
• rs777061524
• NM_001099404.2:c.1889C>G

Variant summary

Our verdict is Uncertain significance. The variant received 1 ACMG points: 2P and 1B. PM2 BP4

The NM_001099404.2(SCN5A):​c.1889C>G​(p.Thr630Arg) variant causes a missense, splice region change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. 2/3 splice prediction tools predict no significant impact on normal splicing. 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. T630K) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 32)
• Consequence: SCN5A NM_001099404.2 missense, splice_region
• Scores: Splicing: ADA: 0.7440
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 1.24
• Publications: 0 publications found

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 Gene-Disease associations (from GenCC):

• Brugada syndrome

  Inheritance: AD Classification: DEFINITIVE, SUPPORTIVE Submitted by: ClinGen, Orphanet
• Brugada syndrome 1

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Ambry Genetics, Laboratory for Molecular Medicine, G2P, Genomics England PanelApp, Labcorp Genetics (formerly Invitae)
• dilated cardiomyopathy

  Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
• dilated cardiomyopathy 1E

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: G2P, Labcorp Genetics (formerly Invitae), Ambry Genetics
• familial long QT syndrome

  Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
• long QT syndrome 3

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae), G2P
• sick sinus syndrome 1

  Inheritance: AD, AR Classification: STRONG, LIMITED Submitted by: Labcorp Genetics (formerly Invitae)
• progressive familial heart block, type 1A

  Inheritance: SD, AD Classification: STRONG, MODERATE Submitted by: Ambry Genetics, Genomics England PanelApp
• atrial standstill

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• familial atrial fibrillation

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• familial isolated dilated cardiomyopathy

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• familial sick sinus syndrome

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• paroxysmal familial ventricular fibrillation

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• progressive familial heart block

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• arrhythmogenic right ventricular cardiomyopathy

  Inheritance: AD Classification: LIMITED Submitted by: ClinGen
• catecholaminergic polymorphic ventricular tachycardia

  Inheritance: AD Classification: NO_KNOWN Submitted by: ClinGen
• short QT syndrome

  Inheritance: AD Classification: NO_KNOWN Submitted by: ClinGen

ACMG classification

Our verdict: Uncertain_significance. The variant received 1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.351851).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
SCN5A	NM_001099404.2	c.1889C>G	p.Thr630Arg	missense_variant, splice_region_variant	Exon 12 of 28	ENST00000413689.6	NP_001092874.1
SCN5A	NM_000335.5	c.1889C>G	p.Thr630Arg	missense_variant, splice_region_variant	Exon 12 of 28	ENST00000423572.7	NP_000326.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
SCN5A	ENST00000413689.6	c.1889C>G	p.Thr630Arg	missense_variant, splice_region_variant	Exon 12 of 28	5	NM_001099404.2	ENSP00000410257.1
SCN5A	ENST00000423572.7	c.1889C>G	p.Thr630Arg	missense_variant, splice_region_variant	Exon 12 of 28	1	NM_000335.5	ENSP00000398266.2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 30

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Uncertain:1

Jul 22, 2023

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces threonine, which is neutral and polar, with arginine, which is basic and polar, at codon 630 of the SCN5A protein (p.Thr630Arg). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with SCN5A-related conditions. 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 tolerated. Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. 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

Jul 20, 2024

All of Us Research Program, National Institutes of Health

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This missense variant replaces threonine with arginine at codon 630 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 SCN5A-related 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	0.082
CardioboostArm	Benign	0.0016
CardioboostCm	Benign	0.00074
BayesDel_addAF	Pathogenic	0.22	D
BayesDel_noAF	Uncertain	0.080
CADD	Benign	22
DANN	Uncertain	0.99
DEOGEN2	Uncertain	0.65	.;.;.;.;.;D;.;.;.
Eigen	Uncertain	0.25
Eigen_PC	Uncertain	0.25
FATHMM_MKL	Uncertain	0.82	D
LIST_S2	Benign	0.85	.;T;T;T;T;T;T;.;T
M_CAP	Pathogenic	0.48	D
MetaRNN	Benign	0.35	T;T;T;T;T;T;T;T;T
MetaSVM	Pathogenic	0.82	D
MutationAssessor	Benign	0.0	.;N;.;.;.;N;.;.;.
PhyloP100		1.2
PrimateAI	Benign	0.43	T
PROVEAN	Benign	-2.2	N;N;N;N;N;N;N;N;N
REVEL	Uncertain	0.57
Sift	Benign	0.21	T;T;T;T;T;T;T;T;T
Sift4G	Benign	0.42	T;T;T;T;T;T;T;T;T
Polyphen		0.99	D;D;.;D;.;P;D;.;.
Vest4		0.39
MutPred		0.29		Loss of glycosylation at T630 (P = 0.0013);Loss of glycosylation at T630 (P = 0.0013);Loss of glycosylation at T630 (P = 0.0013);Loss of glycosylation at T630 (P = 0.0013);Loss of glycosylation at T630 (P = 0.0013);Loss of glycosylation at T630 (P = 0.0013);Loss of glycosylation at T630 (P = 0.0013);Loss of glycosylation at T630 (P = 0.0013);Loss of glycosylation at T630 (P = 0.0013);
MVP		0.78
MPC		0.91
ClinPred		0.54	D
GERP RS		4.1
Varity_R		0.15
gMVP		0.72
Mutation Taster		=22/78	disease causing

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Benign	0.74
dbscSNV1_RF	Benign	0.59
SpliceAI score (max)		0.24		Details are displayed if max score is > 0.2
DS_DL_spliceai		0.24		Position offset: -1

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

Other links and lift over

dbSNP: rs777061524; hg19: chr3-38645204;