chr17-63948027-T-C

Variant names:

• chr17-63948027-T-C
• rs773489142
• NM_000334.4:c.3181A>G

Variant summary

Our verdict is Uncertain significance. The variant received 0 ACMG points: 1P and 1B. PP2 BP4

The NM_000334.4(SCN4A):​c.3181A>G​(p.Ile1061Val) variant causes a missense change. The variant allele was found at a frequency of 0.00000411 in 1,460,582 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000041 (0 hom.)
• Consequence: SCN4A NM_000334.4 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 5.02
• Publications: 0 publications found

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

ACMG classification

Our verdict: Uncertain_significance. The variant received 0 ACMG points.

• 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.
• BP4: Computational evidence support a benign effect (MetaRNN=0.31193846).

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.3181A>G	p.Ile1061Val	missense	Exon 17 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.3181A>G	p.Ile1061Val	missense	Exon 17 of 24	ENSP00000396320.1
	SCN4A	ENST00000584310.1	TSL:4	n.504A>G		non_coding_transcript_exon	Exon 3 of 3

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD2 exomes AF: 0.00000805 AC: 2 AN: 248580 AF XY: 0.0000148

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: 0.00

Gnomad NFE exome AF: 0.0000178

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000411 AC: 6 AN: 1460582 Hom.: 0 Cov.: 33 AF XY: 0.00000551 AC XY: 4 AN XY: 726450

African (AFR) AF: 0.00 AC: 0 AN: 33456

American (AMR) AF: 0.00 AC: 0 AN: 44672

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26088

East Asian (EAS) AF: 0.00 AC: 0 AN: 39652

South Asian (SAS) AF: 0.00 AC: 0 AN: 86168

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53380

Middle Eastern (MID) AF: 0.000174 AC: 1 AN: 5760

European-Non Finnish (NFE) AF: 0.00000450 AC: 5 AN: 1111088

Other (OTH) AF: 0.00 AC: 0 AN: 60318

GnomAD4 genome Cov.: 33

Alfa AF: 0.0000312 Hom.: 0

ExAC AF: 0.0000165 AC: 2

EpiCase AF: 0.00

EpiControl AF: 0.0000595

ClinVar

ClinVar submissions as Germline

Significance: Uncertain significance

Revision: criteria provided, multiple submitters, no conflicts

Pathogenic	VUS	Benign	Condition
-	1	-	not specified (1)
-	1	-	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 (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.11
BayesDel_addAF	Uncertain	0.10	D
BayesDel_noAF	Uncertain	-0.080
CADD	Uncertain	24
DANN	Uncertain	0.99
DEOGEN2	Uncertain	0.67	D
Eigen	Benign	-0.15
Eigen_PC	Benign	0.024
FATHMM_MKL	Uncertain	0.91	D
LIST_S2	Uncertain	0.94	D
M_CAP	Benign	0.056	D
MetaRNN	Benign	0.31	T
MetaSVM	Uncertain	0.64	D
MutationAssessor	Benign	0.79	N
PhyloP100		5.0
PrimateAI	Uncertain	0.72	T
PROVEAN	Benign	-0.79	N
REVEL	Uncertain	0.34
Sift	Benign	0.11	T
Sift4G	Benign	0.41	T
Polyphen		0.077	B
Vest4		0.37
MutPred		0.45		Loss of helix (P = 0.1299)
MVP		0.83
MPC		0.23
ClinPred		0.41	T
GERP RS		4.5
Varity_R		0.36
gMVP		0.55
Mutation Taster		=74/26	polymorphism

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.030		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: rs773489142; hg19: chr17-62025387;