3-38550878-G-T

Position:

• chr3-38550878-G-T

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 5P and 2B. PM2 PM5 PP2 BP4_Moderate

The NM_000335.5(SCN5A):​c.5491C>A​(p.Gln1831Lys) variant causes a missense change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. 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. Q1831E) has been classified as Pathogenic.

• Frequency: Genomes: not found (cov: 33)
• Consequence: SCN5A NM_000335.5 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 4.72

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 (HGNC:):

ACMG classification

Verdict is Uncertain_significance. Variant got 3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr3-38550878-G-C is described in Lovd as [Pathogenic].
• PP2: Missense variant in gene, where missense usually causes diseases (based on misZ statistic), SCN5A. . Gene score misZ 2.7504 (greater than the threshold 3.09). Trascript score misZ 4.8279 (greater than threshold 3.09). GenCC has associacion of gene with 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.
• BP4: Computational evidence support a benign effect (MetaRNN=0.070008636).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
SCN5A	NM_001099404.2	c.5494C>A	p.Gln1832Lys	missense_variant	28/28	ENST00000413689.6	NP_001092874.1
SCN5A	NM_000335.5	c.5491C>A	p.Gln1831Lys	missense_variant	28/28	ENST00000423572.7	NP_000326.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
SCN5A	ENST00000413689.6	c.5494C>A	p.Gln1832Lys	missense_variant	28/28	5	NM_001099404.2	ENSP00000410257.1
SCN5A	ENST00000423572.7	c.5491C>A	p.Gln1831Lys	missense_variant	28/28	1	NM_000335.5	ENSP00000398266.2

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 33

Bravo AF: 0.00000378

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

Labcorp Genetics (formerly Invitae), Labcorp

Mar 05, 2019

This variant has not been reported in the literature in individuals with SCN5A-related conditions. 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. Algorithms developed to predict the effect of missense changes on protein structure and function output the following: SIFT: "Tolerated"; PolyPhen-2: "Benign"; Align-GVGD: "Class C0". The lysine amino acid residue is found in multiple mammalian species, suggesting that this missense change does not adversely affect protein function. These predictions have not been confirmed by published functional studies and their clinical significance is uncertain. This variant is not present in population databases (ExAC no frequency). This sequence change replaces glutamine with lysine at codon 1832 of the SCN5A protein (p.Gln1832Lys). The glutamine residue is moderately conserved and there is a small physicochemical difference between glutamine and lysine. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.077
CardioboostCm	Uncertain	0.19
BayesDel_addAF	Uncertain	0.10	D
BayesDel_noAF	Benign	-0.090
CADD	Benign	18
DANN	Benign	0.94
DEOGEN2	Benign	0.34	.;.;.;.;.;T;.;.;.
Eigen	Benign	-0.58
Eigen_PC	Benign	-0.24
FATHMM_MKL	Uncertain	0.77	D
LIST_S2	Benign	0.75	.;T;T;T;T;T;T;.;T
M_CAP	Uncertain	0.16	D
MetaRNN	Benign	0.070	T;T;T;T;T;T;T;T;T
MetaSVM	Uncertain	-0.19	T
MutationAssessor	Benign	-2.2	.;.;.;.;.;N;.;.;.
PrimateAI	Benign	0.47	T
PROVEAN	Benign	0.52	N;N;N;N;N;N;N;N;N
REVEL	Uncertain	0.29
Sift	Benign	1.0	T;T;T;T;T;T;T;T;T
Sift4G	Benign	1.0	T;T;T;T;T;T;T;T;T
Polyphen		0.040	B;B;.;B;.;B;B;.;.
Vest4		0.060
MutPred		0.42		.;.;Gain of methylation at Q1832 (P = 0.0259);.;.;Gain of methylation at Q1832 (P = 0.0259);.;.;.;
MVP		0.41
MPC		0.67
ClinPred		0.32	T
GERP RS		4.8
Varity_R		0.36
gMVP		0.94

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: rs199473320; hg19: chr3-38592369;