17-63951615-T-G

Variant summary

Our verdict is Likely benign. Variant got -2 ACMG points: 0P and 2B. BP4_Moderate

The NM_000334.4(SCN4A):c.2662A>C(p.Lys888Gln) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000136 in 1,613,786 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 12/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

Frequency

Genomes: 𝑓 0.000053 ( 0 hom., cov: 32)

Exomes 𝑓: 0.00015 ( 0 hom. )

Consequence

SCN4A
NM_000334.4 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:4

Conservation

PhyloP100: 3.32

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_benign. Variant got -2 ACMG points.

BP4

Computational evidence support a benign effect (MetaRNN=0.2600485).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
SCN4A	NM_000334.4 linkuse as main transcript	c.2662A>C	p.Lys888Gln	missense_variant	14/24	ENST00000435607.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
SCN4A	ENST00000435607.3 linkuse as main transcript	c.2662A>C	p.Lys888Gln	missense_variant	14/24	1	NM_000334.4	P1

Frequencies

GnomAD3 genomes

AF:

0.0000526

AC:

AN:

152074

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000483

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:

0.0000882

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000281

AC:

AN:

248852

Hom.:

AF XY:

0.0000222

AC XY:

AN XY:

135044

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.0000290

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000532

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.000145

AC:

212

AN:

1461594

Hom.:

Cov.:

AF XY:

0.000142

AC XY:

103

AN XY:

727064

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.000187

Gnomad4 OTH exome

AF:

0.0000663

GnomAD4 genome

AF:

0.0000526

AC:

AN:

152192

Hom.:

Cov.:

AF XY:

0.0000403

AC XY:

AN XY:

74406

show subpopulations

Gnomad4 AFR

AF:

0.0000482

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:

0.0000882

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000579

Hom.:

Bravo

AF:

0.0000529

ExAC

AF:

0.0000165

AC:

EpiCase

AF:

0.0000545

EpiControl

AF:

0.0000593

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:4

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Inborn genetic diseases

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Dec 12, 2023

The c.2662A>C (p.K888Q) alteration is located in exon 14 (coding exon 14) of the SCN4A gene. This alteration results from a A to C substitution at nucleotide position 2662, causing the lysine (K) at amino acid position 888 to be replaced by a glutamine (Q). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Hyperkalemic periodic paralysis

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Jan 15, 2024

This sequence change replaces lysine, which is basic and polar, with glutamine, which is neutral and polar, at codon 888 of the SCN4A protein (p.Lys888Gln). This variant is present in population databases (rs202155883, gnomAD 0.005%). This variant has not been reported in the literature in individuals affected with SCN4A-related conditions. ClinVar contains an entry for this variant (Variation ID: 477407). 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 not expected to disrupt SCN4A protein function with a negative predictive value of 95%. 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. -

not provided

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Revvity Omics, Revvity

Sep 08, 2022

- -

Paramyotonia congenita of Von Eulenburg;C0238357:Hyperkalemic periodic paralysis;C2750061:Hypokalemic periodic paralysis, type 2;C2931826:Potassium-aggravated myotonia;C3280112:Congenital myasthenic syndrome 16;C3714580:Hypokalemic periodic paralysis, type 1

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Fulgent Genetics, Fulgent Genetics

Apr 11, 2022

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.098

BayesDel_addAF

Benign

-0.16

BayesDel_noAF

Benign

-0.31

Cadd

Uncertain

Dann

Uncertain

0.99

DEOGEN2

Benign

0.31

Eigen

Benign

0.10

Eigen_PC

Benign

0.18

FATHMM_MKL

Pathogenic

0.98

LIST_S2

Benign

0.30

M_CAP

Uncertain

0.11

MetaRNN

Benign

0.26

MetaSVM

Benign

-0.30

MutationAssessor

Benign

0.60

MutationTaster

Benign

0.55

N;N

PrimateAI

Benign

0.45

PROVEAN

Benign

-1.2

REVEL

Uncertain

0.30

Sift

Benign

0.056

Sift4G

Benign

0.23

Polyphen

0.47

Vest4

0.38

MVP

0.72

MPC

0.70

ClinPred

0.28

GERP RS

4.7

Varity_R

0.27

gMVP

0.48

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