NM_000334.4:c.2023C>T

Variant names:

Variant summary

Our verdict is Pathogenic. Variant got 16 ACMG points: 16P and 0B. PM1PM5PP3_StrongPP5_Very_Strong

The NM_000334.4(SCN4A):c.2023C>T(p.Arg675Trp) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000056 in 1,608,322 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 Likely pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R675G) has been classified as Pathogenic.

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 32)

Exomes 𝑓: 0.0000048 ( 0 hom. )

Consequence

SCN4A
NM_000334.4 missense

Scores

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:8O:1

Conservation

PhyloP100: 1.08

Variant links:

Genes affected

SCN4A (HGNC:10591): (sodium voltage-gated channel alpha subunit 4) Voltage-gated sodium channels are transmembrane glycoprotein complexes composed of a large alpha subunit with 24 transmembrane domains 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 alpha subunit gene family. It is expressed in skeletal muscle, and mutations in this gene have been linked to several myotonia and periodic paralysis disorders. [provided by RefSeq, Jul 2008]

SCN4A links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 16 ACMG points.

PM1

In a transmembrane_region Helical; Name=S4 of repeat II (size 17) in uniprot entity SCN4A_HUMAN there are 9 pathogenic changes around while only 0 benign (100%) in NM_000334.4

PM5

Other missense variant is known to change same aminoacid residue: Variant chr17-63957515-G-C is described in Lovd as [Pathogenic].

PP3

MetaRNN computational evidence supports a deleterious effect, 0.994

PP5

Variant 17-63957515-G-A is Pathogenic according to our data. Variant chr17-63957515-G-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 5902.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
SCN4A	NM_000334.4 link	c.2023C>T	p.Arg675Trp	missense_variant	Exon 13 of 24	ENST00000435607.3	NP_000325.4	P35499

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
SCN4A	ENST00000435607.3 link	c.2023C>T	p.Arg675Trp	missense_variant	Exon 13 of 24	1	NM_000334.4	ENSP00000396320.1		P35499

Frequencies

GnomAD3 genomes

AF:

0.0000132

AC:

AN:

152056

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

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:

0.000956

GnomAD3 exomes

AF:

0.0000123

AC:

AN:

243902

Hom.:

AF XY:

0.0000226

AC XY:

AN XY:

132538

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.0000292

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:

0.00000915

Gnomad OTH exome

AF:

0.000168

GnomAD4 exome

AF:

0.00000481

AC:

AN:

1456266

Hom.:

Cov.:

AF XY:

0.00000553

AC XY:

AN XY:

723622

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.0000225

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.0000252

Gnomad4 SAS exome

AF:

0.0000233

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00000271

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

AF:

0.0000132

AC:

AN:

152056

Hom.:

Cov.:

AF XY:

0.0000135

AC XY:

AN XY:

74282

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.00

Gnomad4 OTH

AF:

0.000956

Bravo

AF:

0.00000378

ExAC

AF:

0.00000826

AC:

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:8Other:1

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not provided

Pathogenic:4

Jun 08, 2016

Athena Diagnostics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Mar 21, 2020

Revvity Omics, Revvity

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Oct 01, 2020

CeGaT Center for Human Genetics Tuebingen

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Nov 19, 2024

GeneDx

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; Not observed at significant frequency in large population cohorts (gnomAD); This variant is associated with the following publications: (PMID: 31708864, 19201608, 19052238, 22016737, 32962503, 24772081, 20301669, 29930533, 22926674, 15596759, 29606556) -

Hyperkalemic periodic paralysis

Pathogenic:2Other:1

Jun 19, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces arginine, which is basic and polar, with tryptophan, which is neutral and slightly polar, at codon 675 of the SCN4A protein (p.Arg675Trp). This variant is present in population databases (rs121908556, gnomAD 0.003%). This missense change has been observed in individuals with autosomal dominant SCN4A-related conditions (PMID: 15596759, 29606556). ClinVar contains an entry for this variant (Variation ID: 5902). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is expected to disrupt SCN4A protein function with a positive predictive value of 95%. Experimental studies have shown that this missense change affects SCN4A function (PMID: 19052238). This variant disrupts the p.Arg675 amino acid residue in SCN4A. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 15596759, 19052238, 22926674). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. For these reasons, this variant has been classified as Pathogenic. -

Dec 30, 2024

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

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant summary: SCN4A c.2023C>T (p.Arg675Trp) results in a non-conservative amino acid change in the encoded protein sequence. Five of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 1.2e-05 in 243902 control chromosomes. c.2023C>T has been reported in the literature in multiple individuals affected with Periodic Hyperkalemic Paralysis (examples: Shin_2024, Stunnenberg_2018, ArzelHezode_2009, Vicart_2004). These data indicate that the variant is very likely to be associated with disease. At least one publication reports experimental evidencethat the variant changes the normal function of the protein (Sokolov_2008). The following publications have been ascertained in the context of this evaluation (PMID: 38951973, 19052238, 15596759, 19201608, 15596759). ClinVar contains an entry for this variant (Variation ID: 5902). To our knowledge, this variant has not been reported in individuals with autosomal recessive Congenital Myopathy. Based on the evidence outlined above, this variant is pathogenic for autosomal dominant Periodic Hyperkalemic Paralysis. -

GeneReviews

Significance: not provided

Review Status: no classification provided

Collection Method: literature only

- -

Paramyotonia congenita of Von Eulenburg

Pathogenic:1

Jul 01, 2020

Institute of Human Genetics Munich, Klinikum Rechts Der Isar, TU München

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Normokalemic periodic paralysis, potassium-sensitive

Pathogenic:1

Dec 14, 2004

OMIM

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: literature only

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

1.0

BayesDel_addAF

Pathogenic

0.47

BayesDel_noAF

Pathogenic

0.52

CADD

Pathogenic

DANN

Pathogenic

1.0

DEOGEN2

Pathogenic

0.99

Eigen

Uncertain

0.57

Eigen_PC

Uncertain

0.37

FATHMM_MKL

Uncertain

0.79

LIST_S2

Uncertain

0.96

M_CAP

Pathogenic

0.79

MetaRNN

Pathogenic

0.99

MetaSVM

Pathogenic

1.0

MutationAssessor

Pathogenic

4.5

PrimateAI

Pathogenic

0.95

PROVEAN

Pathogenic

-7.7

REVEL

Pathogenic

0.94

Sift

Pathogenic

0.0

Sift4G

Uncertain

0.0030

Polyphen

1.0

Vest4

0.98

MutPred

0.96

Gain of catalytic residue at L673 (P = 0.0118);

MVP

0.97

MPC

0.92

ClinPred

1.0

GERP RS

1.4

Varity_R

0.97

gMVP

0.98

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

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