rs776925980

Variant names:

• chr3-38633243-G-A
• rs776925980
• NM_001099404.2:c.65C>T

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 2P and 0B. PM2

The NM_001099404.2(SCN5A):​c.65C>T​(p.Ala22Val) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000274 in 1,460,876 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000027 (0 hom.)
• Consequence: SCN5A NM_001099404.2 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:5
• Conservation: PhyloP100: 3.51
• Publications: 1 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 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
SCN5A	NM_001099404.2	c.65C>T	p.Ala22Val	missense_variant	Exon 2 of 28	ENST00000413689.6	NP_001092874.1
SCN5A	NM_000335.5	c.65C>T	p.Ala22Val	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.65C>T	p.Ala22Val	missense_variant	Exon 2 of 28	5	NM_001099404.2	ENSP00000410257.1
SCN5A	ENST00000423572.7	c.65C>T	p.Ala22Val	missense_variant	Exon 2 of 28	1	NM_000335.5	ENSP00000398266.2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD2 exomes AF: 0.00000804 AC: 2 AN: 248738 AF XY: 0.00000741

Gnomad AFR exome AF: 0.000129

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000274 AC: 4 AN: 1460876 Hom.: 0 Cov.: 34 AF XY: 0.00000413 AC XY: 3 AN XY: 726776

African (AFR) AF: 0.0000597 AC: 2 AN: 33478

American (AMR) AF: 0.00 AC: 0 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

East Asian (EAS) AF: 0.00 AC: 0 AN: 39698

South Asian (SAS) AF: 0.00 AC: 0 AN: 86254

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 52646

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5724

European-Non Finnish (NFE) AF: 0.00000180 AC: 2 AN: 1111848

Other (OTH) AF: 0.00 AC: 0 AN: 60368

GnomAD4 genome Cov.: 32

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000378

ExAC AF: 0.00000827 AC: 1

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:5

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Uncertain:3

May 28, 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 valine, which is neutral and non-polar, at codon 22 of the SCN5A protein (p.Ala22Val). The frequency data for this variant in the population databases is considered unreliable, as metrics indicate poor data quality at this position in the gnomAD database. This variant has not been reported in the literature in individuals affected with SCN5A-related conditions. ClinVar contains an entry for this variant (Variation ID: 281662). 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. 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. -

Jul 10, 2015

Eurofins Ntd Llc (ga)

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Dec 09, 2024

GeneDx

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; Has not been previously published as pathogenic or benign to our knowledge -

SUDDEN INFANT DEATH SYNDROME;C1832680:Dilated cardiomyopathy 1E;C1837845:Sick sinus syndrome 1;C1859062:Long QT syndrome 3;C1879286:Progressive familial heart block, type 1A;C2751898:Ventricular fibrillation, paroxysmal familial, type 1;C3151464:Atrial fibrillation, familial, 10;C4551804:Brugada syndrome 1 Uncertain:2

-

Center for Genomics, Ann and Robert H. Lurie Children's Hospital of Chicago

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

SCN5A NM_198056.2 exon 2 p.Ala22Val (c.65C>T): This variant has not been reported in the literature but is present in 0.01% (2/15454) of African alleles in the Genome Aggregation Database (https://gnomad.broadinstitute.org/variant/3-38674734-G-A). This variant is present in ClinVar (Variation ID:281662). Evolutionary conservation and computational predictive tools suggest that this variant may impact the protein. In summary, data on this variant is insufficient for disease classification. Therefore, the clinical significance of this variant is uncertain. -

Jul 22, 2021

Fulgent Genetics, Fulgent Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.15
CardioboostArm	Benign	0.000025
CardioboostCm	Benign	0.0040
BayesDel_addAF	Pathogenic	0.18	D
BayesDel_noAF	Uncertain	0.010
CADD	Benign	20
DANN	Pathogenic	1.0
DEOGEN2	Uncertain	0.69	.;.;.;.;.;D;.;.;.;T;T
Eigen	Uncertain	0.58
Eigen_PC	Uncertain	0.53
FATHMM_MKL	Uncertain	0.95	D
LIST_S2	Uncertain	0.90	.;D;D;D;D;D;D;.;D;D;D
M_CAP	Pathogenic	0.29	D
MetaRNN	Uncertain	0.71	D;D;D;D;D;D;D;D;D;D;D
MetaSVM	Uncertain	0.53	D
MutationAssessor	Uncertain	2.0	.;M;.;.;.;M;.;.;.;.;.
PhyloP100		3.5
PrimateAI	Uncertain	0.55	T
PROVEAN	Uncertain	-3.1	D;D;D;D;D;D;D;D;D;.;D
REVEL	Uncertain	0.57
Sift	Benign	0.076	T;T;T;T;T;T;T;T;T;.;D
Sift4G	Benign	0.15	T;T;T;T;T;T;T;T;T;T;.
Polyphen		1.0	D;D;.;D;.;D;D;.;.;.;.
Vest4		0.19
MutPred		0.33		Gain of helix (P = 0.0325);Gain of helix (P = 0.0325);Gain of helix (P = 0.0325);Gain of helix (P = 0.0325);Gain of helix (P = 0.0325);Gain of helix (P = 0.0325);Gain of helix (P = 0.0325);Gain of helix (P = 0.0325);Gain of helix (P = 0.0325);Gain of helix (P = 0.0325);Gain of helix (P = 0.0325);
MVP		0.82
MPC		1.1
ClinPred		0.94	D
GERP RS		4.4
PromoterAI		-0.035	Neutral
Varity_R		0.24
gMVP		0.60
Mutation Taster		=7/93	disease causing

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

Other links and lift over

dbSNP: rs776925980; hg19: chr3-38674734;