chr3-38575360-G-C

Variant names:

• chr3-38575360-G-C
• rs775488050
• NM_001099404.2:c.3603C>G

Variant summary

Our verdict is Uncertain significance. Variant got 5 ACMG points: 5P and 0B. PM2 PP2 PP3_Moderate

The NM_000335.5(SCN5A):​c.3600C>G​(p.Ile1200Met) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. 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)
• Consequence: SCN5A NM_000335.5 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: -2.27

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 5 ACMG points.

• 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, 0.934

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
SCN5A	NM_001099404.2	c.3603C>G	p.Ile1201Met	missense_variant	Exon 20 of 28	ENST00000413689.6	NP_001092874.1
SCN5A	NM_000335.5	c.3600C>G	p.Ile1200Met	missense_variant	Exon 20 of 28	ENST00000423572.7	NP_000326.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
SCN5A	ENST00000413689.6	c.3603C>G	p.Ile1201Met	missense_variant	Exon 20 of 28	5	NM_001099404.2	ENSP00000410257.1
SCN5A	ENST00000423572.7	c.3600C>G	p.Ile1200Met	missense_variant	Exon 20 of 28	1	NM_000335.5	ENSP00000398266.2

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD3 exomes AF: 0.00000406 AC: 1 AN: 246428 Hom.: 0 AF XY: 0.00 AC XY: 0 AN XY: 133394

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000898

Gnomad OTH exome AF: 0.00

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 33

ExAC AF: 0.00000824 AC: 1

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Uncertain:1

Jul 13, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces isoleucine, which is neutral and non-polar, with methionine, which is neutral and non-polar, at codon 1201 of the SCN5A protein (p.Ile1201Met). 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 missense change has been observed in individual(s) with Brugada syndrome (PMID: 30193851). 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. 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	Benign	0.27
CardioboostCm	Pathogenic	0.99
BayesDel_addAF	Pathogenic	0.30	D
BayesDel_noAF	Pathogenic	0.20
CADD	Benign	15
DANN	Uncertain	0.99
DEOGEN2	Pathogenic	0.82	.;.;.;.;.;D;.;.;.
Eigen	Benign	-0.46
Eigen_PC	Benign	-0.66
FATHMM_MKL	Benign	0.33	N
LIST_S2	Uncertain	0.93	.;D;D;D;D;D;D;.;D
M_CAP	Pathogenic	0.74	D
MetaRNN	Pathogenic	0.93	D;D;D;D;D;D;D;D;D
MetaSVM	Uncertain	0.43	D
MutationAssessor	Pathogenic	2.9	.;.;.;.;.;M;.;.;.
PrimateAI	Uncertain	0.67	T
PROVEAN	Uncertain	-2.9	D;D;D;D;D;D;D;D;D
REVEL	Pathogenic	0.68
Sift	Uncertain	0.015	D;D;D;D;D;D;D;D;D
Sift4G	Uncertain	0.012	D;D;D;D;D;D;D;D;D
Polyphen		0.98	D;P;.;D;.;P;D;.;.
Vest4		0.89
MutPred		0.76		Loss of helix (P = 0.0444);.;Loss of helix (P = 0.0444);Loss of helix (P = 0.0444);.;Loss of helix (P = 0.0444);.;.;.;
MVP		0.96
MPC		1.4
ClinPred		0.93	D
GERP RS		-3.5
Varity_R		0.48
gMVP		0.87

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: rs775488050; hg19: chr3-38616851;