Variant 3-38557231-C-T details in Genebe, Genetics Data Aggregator

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PM2PP3_Strong

The NM_001099404.2(SCN5A):c.4299G>A(p.Gly1433=) variant causes a splice region, synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,384 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Uncertain significance (★★).

Frequency

Genomes: not found (cov: 33)

Exomes 𝑓: 6.8e-7 ( 0 hom. )

Consequence

SCN5A
NM_001099404.2 splice_region, synonymous

Scores

Splicing: ADA: 0.9999

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:2

Conservation

PhyloP100: 1.38

Variant links:

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 links:

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ACMG classification

Classification made for transcript

Verdict is Likely_pathogenic. Variant got 6 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

PP3

Splicing scoreres supports a deletorius effect: Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF, max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
SCN5A	NM_001099404.2 linkuse as main transcript	c.4299G>A	p.Gly1433=	splice_region_variant, synonymous_variant	24/28	ENST00000413689.6	NP_001092874.1
SCN5A	NM_000335.5 linkuse as main transcript	c.4296G>A	p.Gly1432=	splice_region_variant, synonymous_variant	24/28	ENST00000423572.7	NP_000326.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
SCN5A	ENST00000413689.6 linkuse as main transcript	c.4299G>A	p.Gly1433=	splice_region_variant, synonymous_variant	24/28	5	NM_001099404.2	ENSP00000410257	P4
SCN5A	ENST00000423572.7 linkuse as main transcript	c.4296G>A	p.Gly1432=	splice_region_variant, synonymous_variant	24/28	1	NM_000335.5	ENSP00000398266	A1	Q14524-2

Frequencies

GnomAD3 genomes

Cov.:

GnomAD3 exomes

AF:

0.00000400

AC:

AN:

249720

Hom.:

AF XY:

0.00000739

AC XY:

AN XY:

135280

show subpopulations

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:

0.0000328

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

6.84e-7

AC:

AN:

1461384

Hom.:

Cov.:

AF XY:

0.00000138

AC XY:

AN XY:

726984

show subpopulations

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:

0.0000116

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

Cov.:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not provided

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Sep 08, 2023

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. Variants that disrupt the consensus splice site are a relatively common cause of aberrant splicing (PMID: 17576681, 9536098). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. This variant has been observed in individual(s) with clinical features of Brugada syndrome (PMID: 20129283). 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 sequence change affects codon 1433 of the SCN5A mRNA. It is a 'silent' change, meaning that it does not change the encoded amino acid sequence of the SCN5A protein. This variant also falls at the last nucleotide of exon 24, which is part of the consensus splice site for this exon. -

Cardiovascular phenotype

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Dec 20, 2023

The c.4299G>A variant (also known as p.G1433G) is located in coding exon 23 of the SCN5A gene. This variant results from a G to A substitution at nucleotide position 4299. This nucleotide substitution does not change the glycine at codon 1433. However, this change occurs in the last base pair of coding exon 23, which makes it likely to have some effect on normal mRNA splicing. This variant has been detected in Brugada syndrome cohorts; however, clinical details were limited (Kapplinger JD et al. Heart Rhythm, 2010 Jan;7:33-46; Chen GX et al. EBioMedicine, 2023 Jan;87:104388). This nucleotide position is well conserved in available vertebrate species. In silico splice site analysis predicts that this alteration will weaken the native splice donor site. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_noAF

Benign

-0.27

CADD

Benign

DANN

Benign

0.88

Splicing

Name

Calibrated prediction

Score

Prediction

dbscSNV1_ADA

Pathogenic

1.0

dbscSNV1_RF

Pathogenic

0.98

SpliceAI score (max)

0.74

Details are displayed if max score is > 0.2

DS_DL_spliceai

0.74

Position offset: 0

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

Publications

LitVar

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over