rs786204839

chr3-38605949-A-Gchr3-38605949-A-T

Variant summary

Our verdict is Likely pathogenic. Variant got 8 ACMG points: 8P and 0B. PVS1_Moderate PM2 PP3_Strong

The NM_001099404.2(SCN5A):c.1338+2T>C variant causes a splice donor change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. 2/2 splice prediction tools predicting alterations to normal splicing. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar.

• Frequency: Genomes: not found (cov: 32)
• Consequence: SCN5A NM_001099404.2 splice_donor
• Scores: Splicing: ADA: 0.9999
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 3.92

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 8 ACMG points.

• PVS1: Splicing variant, NOT destroyed by nmd, known LOF gene, truncates exone, which is 0.0325566 fraction of the gene. Cryptic splice site detected, with MaxEntScore 8.2, offset of 4, new splice context is: cggGTgagc. Cryptic site results in frameshift change. If cryptic site found is not functional and variant results in exon loss, it results in inframe change.
• PM2: Very rare variant in population databases, with high coverage
• PP3: Splicing scoreres supports a deletorius effect: Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF. No scorers claiming Uncertain. No scorers claiming Benign.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
SCN5A	NM_000335.5	c.1338+2T>C		splice_donor_variant		ENST00000423572.7
SCN5A	NM_001099404.2	c.1338+2T>C		splice_donor_variant		ENST00000413689.6

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
SCN5A	ENST00000413689.6	c.1338+2T>C		splice_donor_variant		5	NM_001099404.2	P4
SCN5A	ENST00000423572.7	c.1338+2T>C		splice_donor_variant		1	NM_000335.5	A1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Pathogenic	0.35
Cadd	Pathogenic	35
Dann	Uncertain	0.99
Eigen	Pathogenic	1.1
Eigen_PC	Pathogenic	0.97
FATHMM_MKL	Uncertain	0.80	D
MutationTaster	Benign	1.0	D;D;D;D;D;D;D;D;D;D
GERP RS		5.5

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.87
SpliceAI score (max)		0.98		Details are displayed if max score is > 0.2
DS_DG_spliceai		0.89		Position offset: -2
DS_DL_spliceai		0.98		Position offset: 2

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

Publications

LitVar

Other links and lift over

dbSNP: rs786204839; hg19: chr3-38647440;