rs73326368

chr17-63968333-G-A

Variant summary

Our verdict is Benign. Variant got -21 ACMG points: 0P and 21B. BP4_Strong BP6_Very_Strong BP7 BA1

The NM_000334.4(SCN4A):c.726C>T(p.Ala242=) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00305 in 1,603,712 control chromosomes in the GnomAD database, including 126 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Benign (★★).

• Frequency:
  • Genomes: 𝑓 0.016 (68 hom., cov: 32)
  • Exomes 𝑓: 0.0016 (58 hom.)
• Consequence: SCN4A NM_000334.4 synonymous
• Clinical Significance: Benign criteria provided, multiple submitters, no conflicts B:9
• Conservation: PhyloP100: -0.951

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]

ACMG classification

Verdict is Benign. Variant got -21 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.78).
• BP6: Variant 17-63968333-G-A is Benign according to our data. Variant chr17-63968333-G-A is described in ClinVar as [Benign]. Clinvar id is 255862.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
• BP7: Synonymous conserved (PhyloP=-0.951 with no splicing effect.
• BA1: GnomAd4 highest subpopulation (AFR) allele frequency at 95% confidence interval = 0.055 is higher than 0.05.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
SCN4A	NM_000334.4	c.726C>T	p.Ala242=	synonymous_variant	6/24	ENST00000435607.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
SCN4A	ENST00000435607.3	c.726C>T	p.Ala242=	synonymous_variant	6/24	1	NM_000334.4	P1

Frequencies

GnomAD3 genomes AF: 0.0165 AC: 2504 AN: 152090 Hom.: 68 Cov.: 32

Gnomad AFR AF: 0.0569

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00688

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: 0.000147

Gnomad OTH AF: 0.0163

GnomAD3 exomes AF: 0.00416 AC: 1002 AN: 241132 Hom.: 21 AF XY: 0.00310 AC XY: 405 AN XY: 130624

Gnomad AFR exome AF: 0.0574

Gnomad AMR exome AF: 0.00271

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.000103

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000925

Gnomad OTH exome AF: 0.00153

GnomAD4 exome AF: 0.00164 AC: 2375 AN: 1451504 Hom.: 58 Cov.: 32 AF XY: 0.00141 AC XY: 1016 AN XY: 720408

Gnomad4 AFR exome AF: 0.0588

Gnomad4 AMR exome AF: 0.00288

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.0000940

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.0000507

Gnomad4 OTH exome AF: 0.00350

GnomAD4 genome AF: 0.0165 AC: 2510 AN: 152208 Hom.: 68 Cov.: 32 AF XY: 0.0153 AC XY: 1140 AN XY: 74414

Gnomad4 AFR AF: 0.0569

Gnomad4 AMR AF: 0.00687

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.000147

Gnomad4 OTH AF: 0.0161

Alfa AF: 0.00969 Hom.: 12

Bravo AF: 0.0189

Asia WGS AF: 0.00289 AC: 11 AN: 3478

ClinVar

Significance: Benign

Submissions summary: Benign:9

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not specified Benign:2

Benign, criteria provided, single submitter	clinical testing	GeneDx	May 04, 2016	This variant is considered likely benign or benign based on one or more of the following criteria: it is a conservative change, it occurs at a poorly conserved position in the protein, it is predicted to be benign by multiple in silico algorithms, and/or has population frequency not consistent with disease. -
Benign, criteria provided, single submitter	clinical testing	PreventionGenetics, part of Exact Sciences	-	- -

Hyperkalemic periodic paralysis Benign:2

Benign, criteria provided, single submitter	clinical testing	Invitae	Jan 30, 2024	- -
Benign, criteria provided, single submitter	clinical testing	Illumina Laboratory Services, Illumina	Jan 13, 2018	This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score and internal cut-off values, a variant classified as benign is not then subjected to further curation. The score for this variant resulted in a classification of benign for this disease. -

Hypokalemic periodic paralysis, type 2 Benign:1

Benign, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jan 13, 2018

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score and internal cut-off values, a variant classified as benign is not then subjected to further curation. The score for this variant resulted in a classification of benign for this disease. -

Paramyotonia congenita of Von Eulenburg Benign:1

Benign, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jan 13, 2018

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score and internal cut-off values, a variant classified as benign is not then subjected to further curation. The score for this variant resulted in a classification of benign for this disease. -

not provided Benign:1

Benign, criteria provided, single submitter

clinical testing

Athena Diagnostics

Sep 26, 2017

- -

Potassium-aggravated myotonia Benign:1

Benign, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jan 13, 2018

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score and internal cut-off values, a variant classified as benign is not then subjected to further curation. The score for this variant resulted in a classification of benign for this disease. -

Congenital myasthenic syndrome 16 Benign:1

Benign, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jan 13, 2018

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score and internal cut-off values, a variant classified as benign is not then subjected to further curation. The score for this variant resulted in a classification of benign for this disease. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.78
Cadd	Benign	7.9
Dann	Benign	0.84

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

Other links and lift over

dbSNP: rs73326368; hg19: chr17-62045693;