17-63941922-G-A

Variant names:

Variant summary

Our verdict is Likely pathogenic. Variant got 7 ACMG points: 7P and 0B. PM1PP3_StrongPP5

The NM_000334.4(SCN4A):c.4360C>T(p.Arg1454Trp) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000869 in 1,610,160 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 Conflicting classifications of pathogenicity (no stars).

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)

Exomes 𝑓: 0.0000089 ( 0 hom. )

Consequence

SCN4A
NM_000334.4 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:3U:1O:1

Conservation

PhyloP100: 0.771

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 Likely_pathogenic. Variant got 7 ACMG points.

PM1

In a transmembrane_region Helical; Name=S4 of repeat IV (size 16) in uniprot entity SCN4A_HUMAN there are 9 pathogenic changes around while only 0 benign (100%) in NM_000334.4

PP3

MetaRNN computational evidence supports a deleterious effect, 0.969

PP5

Variant 17-63941922-G-A is Pathogenic according to our data. Variant chr17-63941922-G-A is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 243042.We mark this variant Likely_pathogenic, oryginal submissions are: {Likely_pathogenic=1, Uncertain_significance=1, not_provided=1}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
SCN4A	NM_000334.4 link	c.4360C>T	p.Arg1454Trp	missense_variant	Exon 24 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.4360C>T	p.Arg1454Trp	missense_variant	Exon 24 of 24	1	NM_000334.4	ENSP00000396320.1		P35499

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152236

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:

0.0000147

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000161

AC:

AN:

248644

Hom.:

AF XY:

0.00000742

AC XY:

AN XY:

134818

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.0000290

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.000109

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00000890

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000892

AC:

AN:

1457924

Hom.:

Cov.:

AF XY:

0.00000828

AC XY:

AN XY:

724520

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.0000224

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.0000505

Gnomad4 SAS exome

AF:

0.0000232

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00000721

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

AF:

0.00000657

AC:

AN:

152236

Hom.:

Cov.:

AF XY:

0.0000134

AC XY:

AN XY:

74372

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:

0.0000147

Gnomad4 OTH

AF:

0.00

Bravo

AF:

0.00000378

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:3Uncertain:1Other:1

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

Congenital myasthenic syndrome 16

Pathogenic:2

May 07, 2022

Experimental Epileptology, AG Lerche, Hertie Institute for Clinical Brain Research

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The variant SCN4A:p.(R1454W) has been identified in compound heterozyous state with a previously unreported variant SCN4A:p.(N1205K). It has an extremely low frequency in gnomAD r2.1 (MAF = 0.00001609 and no homozygotes). It is located in the voltage sensor domain (S4) which is a mutational hotspot and multiple lines of computational evidence support a deleterious effect (CADD: 25.9, GERP++: 2.7, PPh2: 0.99, SIFT: 0). It was first reported in homozygous state in an individual who suffered from muscle weakness consistent with a diagnosis of autosomal recessive Congenital Myasthenic Syndrome 16 (MIM: #614198). Functional characterization in a heterologous expression system showed a net loss of funtion with enhanced fast and slow inactivation with slow recovery (PMID: 26659129). It was therefore classified as likely pathogenic (ACMG/AMP criteria: PS3, PM1, PM2, PP3). -

Jul 16, 2024

OMIM

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: literature only

- -

Congenital myopathy 22A, classic

Pathogenic:1

Jul 16, 2024

OMIM

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: literature only

- -

Hyperkalemic periodic paralysis

Uncertain:1

Jul 07, 2019

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant has been observed in the homozygous state in an individual affected with congenital myasthenic syndrome who also experienced episodes of periodic paralysis (PMID: 26659129). ClinVar contains an entry for this variant (Variation ID: 243042). 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. This variant has been reported to affect SCN4A protein function (PMID: 26659129). This variant is not present in population databases (ExAC no frequency). This sequence change replaces arginine with tryptophan at codon 1454 of the SCN4A protein (p.Arg1454Trp). The arginine residue is highly conserved and there is a moderate physicochemical difference between arginine and tryptophan. -

Congenital myasthenic syndrome

Other:1

GeneReviews

Significance: not provided

Review Status: no classification provided

Collection Method: literature only

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.99

BayesDel_addAF

Pathogenic

0.30

BayesDel_noAF

Pathogenic

0.42

CADD

Uncertain

DANN

Uncertain

1.0

DEOGEN2

Pathogenic

0.99

Eigen

Uncertain

0.34

Eigen_PC

Benign

0.047

FATHMM_MKL

Benign

0.38

LIST_S2

Pathogenic

1.0

M_CAP

Pathogenic

0.69

MetaRNN

Pathogenic

0.97

MetaSVM

Pathogenic

1.0

MutationAssessor

Pathogenic

5.1

PrimateAI

Pathogenic

0.90

PROVEAN

Pathogenic

-7.3

REVEL

Pathogenic

0.82

Sift

Pathogenic

0.0

Sift4G

Pathogenic

0.0

Polyphen

1.0

Vest4

0.93

MutPred

0.77

Gain of catalytic residue at L1452 (P = 0.0302);

MVP

0.93

MPC

0.92

ClinPred

0.99

GERP RS

2.7

Varity_R

0.88

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