rs372405305

Variant names:

• chr3-38566401-A-G
• rs372405305
• NM_001099404.2:c.3840+8T>C

Variant summary

Our verdict is Benign. The variant received -16 ACMG points: 0P and 16B. BP4_Strong BP6_Very_Strong BS1

The NM_001099404.2(SCN5A):​c.3840+8T>C variant causes a splice region, intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000391 in 1,612,402 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 predict no significant impact on normal splicing. Variant has been reported in ClinVar as Likely benign (★★).

• Frequency:
  • Genomes: 𝑓 0.00025 (0 hom., cov: 33)
  • Exomes 𝑓: 0.000017 (0 hom.)
• Consequence: SCN5A NM_001099404.2 splice_region, intron
• Scores: Splicing: ADA: 0.00002733
• Clinical Significance: Benign/Likely benign criteria provided, multiple submitters, no conflicts B:4
• Conservation: PhyloP100: -0.0750
• Publications: 0 publications found

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 Gene-Disease associations (from GenCC):

• Brugada syndrome

  Inheritance: AD Classification: DEFINITIVE, SUPPORTIVE Submitted by: ClinGen, Orphanet
• Brugada syndrome 1

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Ambry Genetics, Laboratory for Molecular Medicine, G2P, Genomics England PanelApp, Labcorp Genetics (formerly Invitae)
• dilated cardiomyopathy

  Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
• dilated cardiomyopathy 1E

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: G2P, Labcorp Genetics (formerly Invitae), Ambry Genetics
• familial long QT syndrome

  Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
• long QT syndrome 3

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae), G2P
• sick sinus syndrome 1

  Inheritance: AD, AR Classification: STRONG, LIMITED Submitted by: Labcorp Genetics (formerly Invitae)
• progressive familial heart block, type 1A

  Inheritance: SD, AD Classification: STRONG, MODERATE Submitted by: Ambry Genetics, Genomics England PanelApp
• atrial standstill

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• familial atrial fibrillation

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• familial isolated dilated cardiomyopathy

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• familial sick sinus syndrome

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• paroxysmal familial ventricular fibrillation

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• progressive familial heart block

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• arrhythmogenic right ventricular cardiomyopathy

  Inheritance: AD Classification: LIMITED Submitted by: ClinGen
• catecholaminergic polymorphic ventricular tachycardia

  Inheritance: AD Classification: NO_KNOWN Submitted by: ClinGen
• short QT syndrome

  Inheritance: AD Classification: NO_KNOWN Submitted by: ClinGen

ACMG classification

Our verdict: Benign. The variant received -16 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.83).
• BP6: Variant 3-38566401-A-G is Benign according to our data. Variant chr3-38566401-A-G is described in ClinVar as Benign/Likely_benign. ClinVar VariationId is 463331.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
• BS1: Variant frequency is greater than expected in population afr. GnomAd4 allele frequency = 0.00025 (38/152260) while in subpopulation AFR AF = 0.00089 (37/41552). AF 95% confidence interval is 0.000664. There are 0 homozygotes in GnomAd4. There are 14 alleles in the male GnomAd4 subpopulation. Median coverage is 33. This position passed quality control check.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
SCN5A	NM_001099404.2	c.3840+8T>C		splice_region_variant, intron_variant	Intron 21 of 27	ENST00000413689.6	NP_001092874.1
SCN5A	NM_000335.5	c.3837+8T>C		splice_region_variant, intron_variant	Intron 21 of 27	ENST00000423572.7	NP_000326.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
SCN5A	ENST00000413689.6	c.3840+8T>C		splice_region_variant, intron_variant	Intron 21 of 27	5	NM_001099404.2	ENSP00000410257.1
SCN5A	ENST00000423572.7	c.3837+8T>C		splice_region_variant, intron_variant	Intron 21 of 27	1	NM_000335.5	ENSP00000398266.2

Frequencies

GnomAD3 genomes AF: 0.000243 AC: 37 AN: 152142 Hom.: 0 Cov.: 33

Gnomad AFR AF: 0.000869

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.0000655

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.00

GnomAD2 exomes AF: 0.0000558 AC: 14 AN: 251100 AF XY: 0.0000295

Gnomad AFR exome AF: 0.000863

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000171 AC: 25 AN: 1460142 Hom.: 0 Cov.: 31 AF XY: 0.0000138 AC XY: 10 AN XY: 726196

African (AFR) AF: 0.000628 AC: 21 AN: 33442

American (AMR) AF: 0.00 AC: 0 AN: 44680

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26104

East Asian (EAS) AF: 0.00 AC: 0 AN: 39662

South Asian (SAS) AF: 0.00 AC: 0 AN: 86208

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53170

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5738

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1110832

Other (OTH) AF: 0.0000663 AC: 4 AN: 60306

GnomAD4 genome AF: 0.000250 AC: 38 AN: 152260 Hom.: 0 Cov.: 33 AF XY: 0.000188 AC XY: 14 AN XY: 74458

African (AFR) AF: 0.000890 AC: 37 AN: 41552

American (AMR) AF: 0.0000654 AC: 1 AN: 15294

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3468

East Asian (EAS) AF: 0.00 AC: 0 AN: 5184

South Asian (SAS) AF: 0.00 AC: 0 AN: 4820

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10612

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 294

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 68012

Other (OTH) AF: 0.00 AC: 0 AN: 2112

Alfa AF: 0.000334 Hom.: 0

Bravo AF: 0.000321

ClinVar

Significance: Benign/Likely benign

Submissions summary: Benign:4

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not specified Benign:2

Sep 05, 2017

GeneDx

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant is considered likely benign or benign based on one or more of the following criteria: it is a conservative change, it occurs at a poorly conserved position in the protein, it is predicted to be benign by multiple in silico algorithms, and/or has population frequency not consistent with disease. -

Apr 29, 2025

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Significance: Benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant summary: SCN5A c.3840+8T>C alters a non-conserved nucleotide located at a position not widely known to affect splicing. Consensus agreement among computation tools predict no significant impact on normal splicing. A publication has reported functional studies showing this variant has no significant impact on normal splicing (O'Neill_2024). The variant allele was found at a frequency of 5.6e-05 in 251100 control chromosomes, predominantly at a frequency of 0.00086 within the African or African-American subpopulation in the gnomAD database. The observed variant frequency within African or African-American control individuals in the gnomAD database is approximately 8.6 fold of the estimated maximal expected allele frequency for a pathogenic variant in SCN5A causing Arrhythmia phenotype (0.0001). To our knowledge, no occurrence of c.3840+8T>C in individuals affected with Arrhythmia have been reported. The following publication has been ascertained in the context of this evaluation (PMID: 39333091). ClinVar contains an entry for this variant (Variation ID: 463331). Based on the evidence outlined above, the variant was classified as benign. -

not provided Benign:2

Dec 07, 2023

ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Jan 28, 2025

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.83
CADD	Benign	0.16
DANN	Benign	0.48
PhyloP100		-0.075
Mutation Taster		=100/0	polymorphism

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Benign	0.000027
dbscSNV1_RF	Benign	0.0060
SpliceAI score (max)		0.010		Details are displayed if max score is > 0.2

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

Other links and lift over

dbSNP: rs372405305; hg19: chr3-38607892;