NM_001040151.2:c.423C>G

Variant names:

• chr11-123642468-G-C
• rs879253730
• NM_001040151.2:c.423C>G

Variant summary

Our verdict is Likely benign. The variant received -2 ACMG points: 2P and 4B. PP3_Moderate BS2

The NM_001040151.2(SCN3B):​c.423C>G​(p.Ile141Met) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000889 in 1,461,892 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★). Synonymous variant affecting the same amino acid position (i.e. I141I) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000089 (0 hom.)
• Consequence: SCN3B NM_001040151.2 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter P:1 U:1
• Conservation: PhyloP100: 2.01
• Publications: 0 publications found

Genes affected

SCN3B (HGNC:20665): (sodium voltage-gated channel beta subunit 3) Voltage-gated sodium channels are transmembrane glycoprotein complexes composed of a large alpha subunit and one or more regulatory beta subunits. They are responsible for the generation and propagation of action potentials in neurons and muscle. This gene encodes one member of the sodium channel beta subunit gene family, and influences the inactivation kinetics of the sodium channel. Two alternatively spliced variants, encoding the same protein, have been identified. [provided by RefSeq, Jul 2008]

SCN3B Gene-Disease associations (from GenCC):

• familial atrial fibrillation

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• Brugada syndrome 7

  Inheritance: AD, Unknown Classification: LIMITED Submitted by: Labcorp Genetics (formerly Invitae), Genomics England PanelApp
• Brugada syndrome 1

  Inheritance: AD Classification: NO_KNOWN Submitted by: ClinGen

ACMG classification

Our verdict: Likely_benign. The variant received -2 ACMG points.

• PP3: MetaRNN computational evidence supports a deleterious effect, 0.845
• BS2: High AC in GnomAdExome4 at 13 AD,Unknown gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
SCN3B	NM_001040151.2	c.423C>G	p.Ile141Met	missense_variant	Exon 4 of 7	ENST00000299333.8	NP_001035241.1
SCN3B	NM_018400.4	c.423C>G	p.Ile141Met	missense_variant	Exon 3 of 6		NP_060870.1
SCN3B	XM_011542897.3	c.423C>G	p.Ile141Met	missense_variant	Exon 4 of 7		XP_011541199.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
SCN3B	ENST00000299333.8	c.423C>G	p.Ile141Met	missense_variant	Exon 4 of 7	1	NM_001040151.2	ENSP00000299333.3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000889 AC: 13 AN: 1461892 Hom.: 0 Cov.: 32 AF XY: 0.00000825 AC XY: 6 AN XY: 727246

African (AFR) AF: 0.00 AC: 0 AN: 33478

American (AMR) AF: 0.00 AC: 0 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

East Asian (EAS) AF: 0.00 AC: 0 AN: 39700

South Asian (SAS) AF: 0.00 AC: 0 AN: 86258

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53420

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 0.0000117 AC: 13 AN: 1112012

Other (OTH) AF: 0.00 AC: 0 AN: 60396

GnomAD4 genome Cov.: 32

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000378

ClinVar

Significance: Uncertain significance

Submissions summary: Pathogenic:1 Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Cardiac arrhythmia Pathogenic:1

Mar 27, 2015

Forensic Genetics Laboratory, Harris County Institute of Forensic Sciences

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

Brugada syndrome 7 Uncertain:1

May 24, 2023

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

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. 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. ClinVar contains an entry for this variant (Variation ID: 224720). This missense change has been observed in individual(s) with Long QT syndrome (PMID: 27435932). This variant is not present in population databases (gnomAD no frequency). This sequence change replaces isoleucine, which is neutral and non-polar, with methionine, which is neutral and non-polar, at codon 141 of the SCN3B protein (p.Ile141Met). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.60
BayesDel_addAF	Pathogenic	0.29	D
BayesDel_noAF	Pathogenic	0.18
CADD	Benign	22
DANN	Uncertain	0.99
DEOGEN2	Uncertain	0.57	D;D;D;T
Eigen	Benign	0.11
Eigen_PC	Benign	0.0068
FATHMM_MKL	Uncertain	0.96	D
LIST_S2	Benign	0.77	.;T;.;.
M_CAP	Pathogenic	0.48	D
MetaRNN	Pathogenic	0.84	D;D;D;D
MetaSVM	Pathogenic	0.88	D
MutationAssessor	Uncertain	2.5	M;M;M;.
PhyloP100		2.0
PrimateAI	Uncertain	0.68	T
PROVEAN	Benign	-2.1	N;N;N;N
REVEL	Uncertain	0.58
Sift	Uncertain	0.0010	D;D;D;D
Sift4G	Uncertain	0.0070	D;D;D;.
Polyphen		1.0	D;D;D;.
Vest4		0.66
MutPred		0.62		Gain of disorder (P = 0.0565);Gain of disorder (P = 0.0565);Gain of disorder (P = 0.0565);Gain of disorder (P = 0.0565);
MVP		0.92
MPC		1.3
ClinPred		0.98	D
GERP RS		-1.6
Varity_R		0.66
gMVP		0.87
Mutation Taster		=3/97	disease causing (ClinVar)

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

Other links and lift over

dbSNP: rs879253730; hg19: chr11-123513176; COSMIC: COSV54798859; COSMIC: COSV54798859;