rs199473132

chr3-38603800-A-G

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 3P and 0B. PM2 PP2

The NM_001099404.2(SCN5A):c.1802T>C(p.Val601Ala) variant causes a missense change. The variant allele was found at a frequency of 0.000000697 in 1,435,748 control chromosomes in the GnomAD database, with no homozygous occurrence. 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. V601L) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 7.0e-7 (0 hom.)
• Consequence: SCN5A NM_001099404.2 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1 O:1
• Conservation: PhyloP100: 6.26

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 3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant where missense usually causes diseases, SCN5A

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
SCN5A	NM_001099404.2	c.1802T>C	p.Val601Ala	missense_variant	12/28	ENST00000413689.6
SCN5A	NM_000335.5	c.1802T>C	p.Val601Ala	missense_variant	12/28	ENST00000423572.7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
SCN5A	ENST00000413689.6	c.1802T>C	p.Val601Ala	missense_variant	12/28	5	NM_001099404.2	P4
SCN5A	ENST00000423572.7	c.1802T>C	p.Val601Ala	missense_variant	12/28	1	NM_000335.5	A1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.97e-7 AC: 1 AN: 1435748 Hom.: 0 Cov.: 31 AF XY: 0.00000141 AC XY: 1 AN XY: 709826

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: 9.13e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1 Other:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Uncertain:1 Other:1

Uncertain significance, criteria provided, single submitter	clinical testing	Invitae	Aug 16, 2021	This sequence change replaces valine with alanine at codon 601 of the SCN5A protein (p.Val601Ala). The valine residue is highly conserved and there is a small physicochemical difference between valine and alanine. 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 conditions. ClinVar contains an entry for this variant (Variation ID: 67690). Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Tolerated"; PolyPhen-2: "Possibly Damaging"; Align-GVGD: "Class C0"). 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. -
not provided, no classification provided	literature only	Cardiovascular Biomedical Research Unit, Royal Brompton & Harefield NHS Foundation Trust	-	This variant has been reported in the following publications (PMID:19841300;PMID:20129283). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.34
CardioboostArm	Benign	0.0026
CardioboostCm	Benign	0.030
BayesDel_addAF	Pathogenic	0.29	D
BayesDel_noAF	Pathogenic	0.17
Cadd	Benign	23
Dann	Uncertain	1.0
Eigen	Uncertain	0.51
Eigen_PC	Uncertain	0.47
FATHMM_MKL	Pathogenic	0.98	D
M_CAP	Pathogenic	0.35	D
MetaRNN	Uncertain	0.70	D;D;D;D;D;D;D;D;D
MetaSVM	Uncertain	0.77	D
MutationTaster	Benign	1.0	D;D;D;D;D;D;D;D;D;D
PrimateAI	Uncertain	0.71	T
PROVEAN	Uncertain	-2.5	N;N;N;N;D;N;N;D;D
REVEL	Uncertain	0.60
Sift	Uncertain	0.0020	D;D;D;D;D;D;D;D;D
Sift4G	Benign	0.12	T;T;T;T;T;T;T;T;T
Polyphen		1.0	D;B;.;D;.;P;D;.;.
Vest4		0.73
MutPred		0.17		Gain of glycosylation at S602 (P = 0.2298);Gain of glycosylation at S602 (P = 0.2298);Gain of glycosylation at S602 (P = 0.2298);Gain of glycosylation at S602 (P = 0.2298);Gain of glycosylation at S602 (P = 0.2298);Gain of glycosylation at S602 (P = 0.2298);Gain of glycosylation at S602 (P = 0.2298);Gain of glycosylation at S602 (P = 0.2298);Gain of glycosylation at S602 (P = 0.2298);
MVP		0.80
MPC		1.2
ClinPred		0.95	D
GERP RS		4.2
Varity_R		0.31
gMVP		0.74

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: rs199473132; hg19: chr3-38645291;