rs199473246

chr3-38557234-C-Achr3-38557234-C-Gchr3-38557234-C-T

Variant summary

Our verdict is Pathogenic. Variant got 11 ACMG points: 11P and 0B. PM1 PM2 PM5 PP2 PP3_Strong

The NM_001099404.2(SCN5A):c.4296G>T(p.Arg1432Ser) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,461,608 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 (★). Another nucleotide change resulting in same amino acid change has been previously reported as Uncertain significancein ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R1432G) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: SCN5A NM_001099404.2 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: -0.0310

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 Pathogenic. Variant got 11 ACMG points.

• PM1: In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 13 uncertain in NM_001099404.2
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr3-38557236-T-C is described in Lovd as [Pathogenic].
• PP2: Missense variant where missense usually causes diseases, SCN5A
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.979

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
SCN5A	NM_001099404.2	c.4296G>T	p.Arg1432Ser	missense_variant	24/28	ENST00000413689.6
SCN5A	NM_000335.5	c.4293G>T	p.Arg1431Ser	missense_variant	24/28	ENST00000423572.7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
SCN5A	ENST00000413689.6	c.4296G>T	p.Arg1432Ser	missense_variant	24/28	5	NM_001099404.2	P4
SCN5A	ENST00000423572.7	c.4293G>T	p.Arg1431Ser	missense_variant	24/28	1	NM_000335.5	A1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1461608 Hom.: 0 Cov.: 30 AF XY: 0.00 AC XY: 0 AN XY: 727104

Gnomad4 AFR exome AF: 0.0000598

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: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Jul 11, 2018

This sequence change replaces arginine with serine at codon 1432 of the SCN5A protein (p.Arg1432Ser). The arginine residue is highly conserved and there is a moderate physicochemical difference between arginine and serine. This variant is not present in population databases (ExAC no frequency). This variant has been observed in an individual affected with Brugada syndrome (Invitae). Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be disruptive, but these predictions have not been confirmed by published functional studies and their clinical significance is uncertain. The observation of one or more missense substitutions at this codon (p.Arg4132Ser and p.Arg4132Gly) in affected individuals suggests that this may be a clinically significant residue (PMID: 28341781, 10727653, 25904541). A different variant (c.4296G>C) giving rise to the same protein effect observed here (p.Arg1432Ser) has been reported in an individual affected with Brugada syndrome (PMID: 28341781) and in an individual affected with long QT syndrome or referred for long QT syndrome clinical genetic testing (PMID: 25904541), indicating that this residue may be critical for protein function. 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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.98
CardioboostArm	Uncertain	0.86
CardioboostCm	Uncertain	0.74
BayesDel_addAF	Pathogenic	0.47	D
BayesDel_noAF	Pathogenic	0.44
Cadd	Benign	22
Dann	Uncertain	1.0
Eigen	Benign	-0.065
Eigen_PC	Benign	-0.17
FATHMM_MKL	Benign	0.72	D
LIST_S2	Benign	0.84	T;T;D;T;T;.;D
M_CAP	Pathogenic	0.88	D
MetaRNN	Pathogenic	0.98	D;D;D;D;D;D;D
MetaSVM	Pathogenic	0.93	D
MutationTaster	Benign	1.0	D;D;D;D;D;D;D;D;D;D
PrimateAI	Uncertain	0.66	T
PROVEAN	Pathogenic	-4.8	D;D;D;D;D;D;D
REVEL	Pathogenic	0.88
Sift	Uncertain	0.0030	D;D;D;D;D;D;D
Sift4G	Uncertain	0.026	D;D;D;D;D;D;D
Polyphen		0.94	P;.;.;P;D;.;.
Vest4		0.91
MutPred		0.86		.;Gain of glycosylation at R1432 (P = 0.0013);.;Gain of glycosylation at R1432 (P = 0.0013);.;.;.;
MVP		1.0
MPC		1.5
ClinPred		1.0	D
GERP RS		-0.64
Varity_R		0.77
gMVP		0.98

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.29		Details are displayed if max score is > 0.2
DS_AG_spliceai		0.29		Position offset: 50

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

Publications

LitVar

Other links and lift over

dbSNP: rs199473246; hg19: chr3-38598725;