rs199473334

Variant names:

• chr3-38550443-A-T
• rs199473334
• NM_001099404.2:c.5929T>A

Variant summary

Our verdict is Likely pathogenic. Variant got 7 ACMG points: 7P and 0B. PM1 PM2 PP2 PP3_Moderate

The NM_000335.5(SCN5A):​c.5926T>A​(p.Tyr1976Asn) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000483 in 1,449,882 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000048 (0 hom.)
• Consequence: SCN5A NM_000335.5 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1 O:1
• Conservation: PhyloP100: 9.32

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 Likely_pathogenic. Variant got 7 ACMG points.

• PM1: In a mutagenesis_site Strongly reduces interaction with NEDD4, NEDD4L or WWP2. (size 0) in uniprot entity SCN5A_HUMAN
• 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.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.891

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
SCN5A	NM_001099404.2	c.5929T>A	p.Tyr1977Asn	missense_variant	Exon 28 of 28	ENST00000413689.6	NP_001092874.1
SCN5A	NM_000335.5	c.5926T>A	p.Tyr1976Asn	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.5929T>A	p.Tyr1977Asn	missense_variant	Exon 28 of 28	5	NM_001099404.2	ENSP00000410257.1
SCN5A	ENST00000423572.7	c.5926T>A	p.Tyr1976Asn	missense_variant	Exon 28 of 28	1	NM_000335.5	ENSP00000398266.2

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 0.00000483 AC: 7 AN: 1449882 Hom.: 0 Cov.: 31 AF XY: 0.00000417 AC XY: 3 AN XY: 719338

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: 0.00000633

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

Bravo AF: 0.00000378

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1 Other:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Uncertain:1

Oct 18, 2023

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces tyrosine, which is neutral and polar, with asparagine, which is neutral and polar, at codon 1977 of the SCN5A protein (p.Tyr1977Asn). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individual(s) with long QT syndrome (PMID: 19841300, 31614475). ClinVar contains an entry for this variant (Variation ID: 68019). 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. Experimental studies have shown that this missense change affects SCN5A function (PMID: 31614475, 31900993). 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. -

Congenital long QT syndrome Other:1

-

Cardiovascular Biomedical Research Unit, Royal Brompton & Harefield NHS Foundation Trust

Significance: not provided

Review Status: no classification provided

Collection Method: literature only

This variant has been reported as associated with Long QT syndrome in the following publications (PMID:19716085;PMID:19841300). This is a literature report, and does not necessarily reflect the clinical interpretation of the Imperial College / Royal Brompton Cardiovascular Genetics laboratory. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.97
CardioboostCm	Benign	0.026
BayesDel_addAF	Pathogenic	0.36	D
BayesDel_noAF	Pathogenic	0.28
CADD	Uncertain	24
DANN	Uncertain	0.99
DEOGEN2	Pathogenic	0.83	.;.;.;.;.;D;.;.;.
Eigen	Uncertain	0.56
Eigen_PC	Uncertain	0.61
FATHMM_MKL	Pathogenic	1.0	D
LIST_S2	Uncertain	0.97	.;D;D;D;D;D;D;.;D
M_CAP	Pathogenic	0.74	D
MetaRNN	Pathogenic	0.89	D;D;D;D;D;D;D;D;D
MetaSVM	Pathogenic	1.0	D
MutationAssessor	Benign	0.81	.;.;.;.;.;L;.;.;.
PrimateAI	Uncertain	0.73	T
PROVEAN	Pathogenic	-8.2	D;D;D;D;D;D;D;D;D
REVEL	Pathogenic	0.84
Sift	Pathogenic	0.0	D;D;D;D;D;D;D;D;D
Sift4G	Uncertain	0.0070	D;D;D;D;D;D;D;D;D
Polyphen		1.0	D;D;.;D;.;P;D;.;.
Vest4		0.85
MutPred		0.70		.;.;Loss of phosphorylation at Y1977 (P = 0.0176);.;.;Loss of phosphorylation at Y1977 (P = 0.0176);.;.;.;
MVP		0.86
MPC		1.8
ClinPred		0.99	D
GERP RS		5.0
Varity_R		0.91
gMVP		0.49

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: rs199473334; hg19: chr3-38591934;