rs148598985

chr3-38556428-G-A

Variant summary

Our verdict is Benign. Variant got -9 ACMG points: 0P and 9B. BP4_Strong BP6 BS2

The NM_001099404.2(SCN5A):c.4437+13C>T variant causes a intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000668 in 1,578,828 control chromosomes in the GnomAD database, including 5 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

• Frequency:
  • Genomes: 𝑓 0.0033 (4 hom., cov: 32)
  • Exomes 𝑓: 0.00038 (1 hom.)
• Consequence: SCN5A NM_001099404.2 intron
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:1 B:14
• Conservation: PhyloP100: 0.130

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 Benign. Variant got -9 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.75).
• BP6: Variant 3-38556428-G-A is Benign according to our data. Variant chr3-38556428-G-A is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 36762.We mark this variant Likely_benign, oryginal submissions are: {Benign=5, Likely_benign=5, Uncertain_significance=1}. Variant chr3-38556428-G-A is described in Lovd as [Benign].
• BS2: High Homozygotes in GnomAd at 4 SD gene

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
SCN5A	NM_000335.5	c.4434+13C>T		intron_variant		ENST00000423572.7
SCN5A	NM_001099404.2	c.4437+13C>T		intron_variant		ENST00000413689.6

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
SCN5A	ENST00000413689.6	c.4437+13C>T		intron_variant		5	NM_001099404.2	P4
SCN5A	ENST00000423572.7	c.4434+13C>T		intron_variant		1	NM_000335.5	A1

Frequencies

GnomAD3 genomes AF: 0.00328 AC: 500 AN: 152224 Hom.: 4 Cov.: 32

Gnomad AFR AF: 0.0112

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00137

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.000207

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000588

Gnomad OTH AF: 0.00431

GnomAD3 exomes AF: 0.000845 AC: 166 AN: 196512 Hom.: 0 AF XY: 0.000744 AC XY: 78 AN XY: 104874

Gnomad AFR exome AF: 0.0103

Gnomad AMR exome AF: 0.00150

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: 0.0000354

Gnomad OTH exome AF: 0.000776

GnomAD4 exome AF: 0.000385 AC: 549 AN: 1426486 Hom.: 1 Cov.: 36 AF XY: 0.000351 AC XY: 248 AN XY: 705894

Gnomad4 AFR exome AF: 0.0121

Gnomad4 AMR exome AF: 0.00152

Gnomad4 ASJ exome AF: 0.000157

Gnomad4 EAS exome AF: 0.0000261

Gnomad4 SAS exome AF: 0.0000369

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.0000302

Gnomad4 OTH exome AF: 0.000811

GnomAD4 genome AF: 0.00331 AC: 505 AN: 152342 Hom.: 4 Cov.: 32 AF XY: 0.00311 AC XY: 232 AN XY: 74494

Gnomad4 AFR AF: 0.0113

Gnomad4 AMR AF: 0.00137

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.000207

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000588

Gnomad4 OTH AF: 0.00427

Alfa AF: 0.00193 Hom.: 0

Bravo AF: 0.00374

Asia WGS AF: 0.000289 AC: 1 AN: 3478

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:1 Benign:14

Revision: criteria provided, conflicting classifications

Submissions by phenotype

not specified Benign:5

Benign, no assertion criteria provided	clinical testing	Clinical Genetics, Academic Medical Center	-	- -
Benign, criteria provided, single submitter	clinical testing	Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine	Mar 19, 2012	c.4437+13C>T in Intron 25 of SCN5A: This variant is not expected to have clinica l significance because it is not located within the splice consensus sequence an d has been identified in 0.9% (30/3228) of African American chromosomes from a b road population by the NHLBI Exome Sequencing Project (http://evs.gs.washington. edu/EVS; dbSNP rs148598985). -
Benign, no assertion criteria provided	clinical testing	Genome Diagnostics Laboratory, University Medical Center Utrecht	-	- -
Benign, no assertion criteria provided	clinical testing	Clinical Genetics DNA and cytogenetics Diagnostics Lab, Erasmus MC, Erasmus Medical Center	-	- -
Benign, criteria provided, single submitter	clinical testing	Women's Health and Genetics/Laboratory Corporation of America, LabCorp	Nov 05, 2019	Variant summary: SCN5A c.4437+13C>T alters a non-conserved nucleotide located close to a canonical splice site and therefore could affect mRNA splicing, leading to a significantly altered protein sequence. 5/5 computational tools predict no significant impact on normal splicing. However, these predictions have yet to be confirmed by functional studies. The variant allele was found at a frequency of 0.0012 in 227906 control chromosomes, predominantly at a frequency of 0.011 within the African or African-American subpopulation in the gnomAD database, including 1 homozygote. The observed variant frequency within African or African-American control individuals in the gnomAD database is approximately 110 fold of the estimated maximal expected allele frequency for a pathogenic variant in SCN5A causing Arrhythmia phenotype (0.0001), strongly suggesting that the variant is a benign polymorphism found primarily in populations of African or African-American origin. To our knowledge, no occurrence of c.4437+13C>T in individuals affected with Arrhythmia and no experimental evidence demonstrating its impact on protein function have been reported. Co-occurrence with another pathogenic variant has been internally reported (TTR c.424G>A, p.V142I), providing supporting evidence for a benign role. One ClinVar submitter (evaluation after 2014) cite the variant as uncertain significance. Based on the evidence outlined above, the variant was classified as benign. -

not provided Benign:3

Benign, criteria provided, single submitter	clinical testing	GeneDx	Mar 03, 2015	- -
Benign, criteria provided, single submitter	clinical testing	Invitae	Jan 29, 2024	- -
Likely benign, no assertion criteria provided	clinical testing	Joint Genome Diagnostic Labs from Nijmegen and Maastricht, Radboudumc and MUMC+	-	- -

Congenital long QT syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jun 14, 2016

- -

Brugada syndrome 1 Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jan 13, 2018

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score and internal cut-off values, a variant classified as likely benign is not then subjected to further curation. The score for this variant resulted in a classification of likely benign for this disease. -

Dilated cardiomyopathy 1E Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jan 13, 2018

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score and internal cut-off values, a variant classified as likely benign is not then subjected to further curation. The score for this variant resulted in a classification of likely benign for this disease. -

Ventricular fibrillation, paroxysmal familial, type 1 Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jan 13, 2018

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score and internal cut-off values, a variant classified as likely benign is not then subjected to further curation. The score for this variant resulted in a classification of likely benign for this disease. -

Sick sinus syndrome 1 Benign:1

Benign, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jan 13, 2018

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score and internal cut-off values, a variant classified as benign is not then subjected to further curation. The score for this variant resulted in a classification of benign for this disease. -

Progressive familial heart block, type 1A Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jan 13, 2018

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score and internal cut-off values, a variant classified as likely benign is not then subjected to further curation. The score for this variant resulted in a classification of likely benign for this disease. -

Long QT syndrome 3 Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jan 13, 2018

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score and internal cut-off values, a variant classified as likely benign is not then subjected to further curation. The score for this variant resulted in a classification of likely benign for this disease. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.75
Cadd	Benign	12
Dann	Benign	0.74

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: rs148598985; hg19: chr3-38597919;