rs80338784

Variant names:

Variant summary

Our verdict is Pathogenic. The variant received 19 ACMG points: 19P and 0B. PM1PM2PM5PP2PP3_StrongPP5_Very_Strong

The NM_000334.4(SCN4A):c.2006G>A(p.Arg669His) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000205 in 1,461,012 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 14/22 in silico tools predict a damaging outcome for this variant. Variant has been reported in ClinVar as Pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R669C) has been classified as Likely pathogenic.

Frequency

Genomes: not found (cov: 32)

Exomes 𝑓: 0.0000021 ( 0 hom. )

Consequence

SCN4A
NM_000334.4 missense

Scores

Clinical Significance

Pathogenic criteria provided, multiple submitters, no conflicts P:4O:2

Conservation

PhyloP100: 7.87

Publications

51 publications found

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 Gene-Disease associations (from GenCC):

hyperkalemic periodic paralysis
Inheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Genomics England PanelApp, Labcorp Genetics (formerly Invitae), G2P, Orphanet
paramyotonia congenita of Von Eulenburg
Inheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Laboratory for Molecular Medicine, Genomics England PanelApp, Labcorp Genetics (formerly Invitae), G2P, Orphanet
SCN4A-related myopathy, autosomal recessive
Inheritance: AR Classification: DEFINITIVE Submitted by: Illumina, ClinGen
hypokalemic periodic paralysis, type 2
Inheritance: AD Classification: STRONG Submitted by: Genomics England PanelApp, Labcorp Genetics (formerly Invitae)
potassium-aggravated myotonia
Inheritance: AD Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae)
congenital myasthenic syndrome 16
Inheritance: AR Classification: STRONG, LIMITED Submitted by: PanelApp Australia, Ambry Genetics, Genomics England PanelApp, Labcorp Genetics (formerly Invitae)
congenital myopathy
Inheritance: AR Classification: STRONG Submitted by: Genomics England PanelApp
congenital myopathy 22A, classic
Inheritance: AR Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae)
acetazolamide-responsive myotonia
Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
hypokalemic periodic paralysis
Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
myotonia fluctuans
Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
myotonia permanens
Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
postsynaptic congenital myasthenic syndrome
Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

SCN4A links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Pathogenic. The variant received 19 ACMG points.

PM1

In a hotspot region, there are 11 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 7 uncertain in NM_000334.4

PM2

Very rare variant in population databases, with high coverage;

PM5

Other missense variant is known to change same aminoacid residue: Variant chr17-63959279-G-A is described in ClinVar as Likely_pathogenic. ClinVar VariationId is 843445.Status of the report is criteria_provided_single_submitter, 1 stars.

PP2

Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 97 curated pathogenic missense variants (we use a threshold of 10). The gene has 19 curated benign missense variants. Gene score misZ: 1.5606 (below the threshold of 3.09). Trascript score misZ: 2.2224 (below the threshold of 3.09). GenCC associations: The gene is linked to congenital myasthenic syndrome 16, paramyotonia congenita of Von Eulenburg, hyperkalemic periodic paralysis, hypokalemic periodic paralysis, type 2, congenital myopathy, hypokalemic periodic paralysis, SCN4A-related myopathy, autosomal recessive, congenital myopathy 22A, classic, potassium-aggravated myotonia, postsynaptic congenital myasthenic syndrome, myotonia fluctuans, myotonia permanens, acetazolamide-responsive myotonia.

PP3

MetaRNN computational evidence supports a deleterious effect, 0.992

PP5

Variant 17-63959278-C-T is Pathogenic according to our data. Variant chr17-63959278-C-T is described in ClinVar as Pathogenic. ClinVar VariationId is 5911.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000334.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	SCN4A	NM_000334.4	MANE Select	c.2006G>A	p.Arg669His	missense	Exon 12 of 24	NP_000325.4

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	SCN4A	ENST00000435607.3	TSL:1 MANE Select	c.2006G>A	p.Arg669His	missense	Exon 12 of 24	ENSP00000396320.1
	SCN4A	ENST00000581514.1	TSL:3	n.*95G>A		downstream_gene	N/A

Frequencies

GnomAD3 genomes

Cov.:

GnomAD2 exomes

AF:

0.00000805

AC:

AN:

248518

AF XY:

0.0000148

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.0000930

Gnomad NFE exome

AF:

0.00

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000205

AC:

AN:

1461012

Hom.:

Cov.:

AF XY:

0.00000275

AC XY:

AN XY:

726742

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33466

American (AMR)

AF:

0.00

AC:

AN:

44712

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26078

East Asian (EAS)

AF:

0.00

AC:

AN:

39690

South Asian (SAS)

AF:

0.00

AC:

AN:

86194

European-Finnish (FIN)

AF:

0.0000562

AC:

AN:

53376

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5758

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

1111402

Other (OTH)

AF:

0.00

AC:

AN:

60336

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.475

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

GnomAD4 genome

Cov.:

Alfa

AF:

0.000122

Hom.:

ExAC

AF:

0.00000826

AC:

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:4Other:2

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Hypokalemic periodic paralysis, type 2

Pathogenic:1Other:1

Apr 01, 2002

OMIM

Significance:Pathogenic

Review Status:no assertion criteria provided

Collection Method:literature only

GeneReviews

Significance:not provided

Review Status:no classification provided

Collection Method:literature only

Hyperkalemic periodic paralysis

Pathogenic:1Other:1

Dec 17, 2021

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 histidine, which is basic and polar, at codon 669 of the SCN4A protein (p.Arg669His). For these reasons, this variant has been classified as Pathogenic. Experimental studies have shown that this missense change affects SCN4A function (PMID: 11102465, 11912116, 21881211, 25024265). Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be disruptive. ClinVar contains an entry for this variant (Variation ID: 5911). This missense change has been observed in individual(s) with hypokalemic periodic paralysis (PMID: 10599760, 18162704, 21841462). In at least one individual the variant was observed to be de novo. It has also been observed to segregate with disease in related individuals. This variant is present in population databases (rs80338784, gnomAD 0.009%).

GeneReviews

Significance:not provided

Review Status:no classification provided

Collection Method:literature only

not provided

Pathogenic:1

Mar 21, 2023

Athena Diagnostics

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The frequency of this variant in the general population is consistent with pathogenicity (http://gnomad.broadinstitute.org). This variant appears to occur de novo in multiple individuals with clinical features of hypokalemic periodic paralysis. Assessment of experimental evidence suggests this variant results in abnormal protein function. (PMID: 11102465, 11912116, 21881211, 25024265) The variant is located in a region that is considered important for protein function and/or structure.

Paramyotonia congenita of Von Eulenburg;C0238357:Hyperkalemic periodic paralysis;C2750061:Hypokalemic periodic paralysis, type 2;C2931826:Potassium-aggravated myotonia;C3280112:Congenital myasthenic syndrome 16;C5830453:Congenital myopathy 22A, classic;C5830501:Congenital myopathy 22B, severe fetal

Pathogenic:1

Mar 13, 2024

Fulgent Genetics, Fulgent Genetics

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Computational scores

Source: dbNSFP v4.9

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.99

BayesDel_addAF

Pathogenic

0.58

BayesDel_noAF

Pathogenic

0.60

CADD

Pathogenic

(source)

DANN

Pathogenic

1.0

DEOGEN2

Pathogenic

0.98

Eigen

Pathogenic

1.0

Eigen_PC

Pathogenic

0.90

FATHMM_MKL

Pathogenic

0.97

LIST_S2

Uncertain

0.96

M_CAP

Pathogenic

0.64

MetaRNN

Pathogenic

0.99

MetaSVM

Pathogenic

1.0

MutationAssessor

Pathogenic

4.0

PhyloP100

7.9

PrimateAI

Pathogenic

0.86

PROVEAN

Pathogenic

-4.8

REVEL

Pathogenic

0.97

Sift

Pathogenic

0.0

Sift4G

Uncertain

0.029

Polyphen

0.99

Vest4

0.98

MutPred

0.96

Loss of MoRF binding (P = 0.0277)

MVP

0.98

MPC

0.99

ClinPred

1.0

GERP RS

4.9

Varity_R

0.91

gMVP

0.93

Mutation Taster

=2/98

disease causing (ClinVar)

(source)

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

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Variant Effect in Transcripts

RefSeq Transcripts

Ensembl Transcripts

Frequencies

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over