rs149726115

chr17-63968060-G-Achr17-63968060-G-T

Variant summary

Our verdict is Benign. Variant got -10 ACMG points: 0P and 10B. BP4_Strong BP6 BP7 BS1

The NM_000334.4(SCN4A):c.999C>T(p.Asn333=) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000821 in 1,613,786 control chromosomes in the GnomAD database, including 3 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

• Frequency:
  • Genomes: 𝑓 0.00053 (0 hom., cov: 32)
  • Exomes 𝑓: 0.00085 (3 hom.)
• Consequence: SCN4A NM_000334.4 synonymous
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:1 B:8
• Conservation: PhyloP100: 1.22

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 -10 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.8).
• BP6: Variant 17-63968060-G-A is Benign according to our data. Variant chr17-63968060-G-A is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 448288.We mark this variant Likely_benign, oryginal submissions are: {Likely_benign=3, Benign=5, Uncertain_significance=1}.
• BP7: Synonymous conserved (PhyloP=1.22 with no splicing effect.
• BS1: Variant frequency is greater than expected in population nfe. gnomad4_exome allele frequency = 0.000851 (1244/1461704) while in subpopulation NFE AF= 0.00104 (1160/1111866). AF 95% confidence interval is 0.000993. There are 3 homozygotes in gnomad4_exome. There are 592 alleles in male gnomad4_exome subpopulation. Median coverage is 32. This position pass quality control queck.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
SCN4A	NM_000334.4	c.999C>T	p.Asn333=	synonymous_variant	6/24	ENST00000435607.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
SCN4A	ENST00000435607.3	c.999C>T	p.Asn333=	synonymous_variant	6/24	1	NM_000334.4	P1

Frequencies

GnomAD3 genomes AF: 0.000533 AC: 81 AN: 152082 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.000169

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.000328

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: 0.000985

Gnomad OTH AF: 0.000961

GnomAD3 exomes AF: 0.000542 AC: 135 AN: 248884 Hom.: 1 AF XY: 0.000578 AC XY: 78 AN XY: 135054

Gnomad AFR exome AF: 0.0000645

Gnomad AMR exome AF: 0.000348

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.000229

Gnomad FIN exome AF: 0.000371

Gnomad NFE exome AF: 0.000915

Gnomad OTH exome AF: 0.000661

GnomAD4 exome AF: 0.000851 AC: 1244 AN: 1461704 Hom.: 3 Cov.: 32 AF XY: 0.000814 AC XY: 592 AN XY: 727136

Gnomad4 AFR exome AF: 0.000179

Gnomad4 AMR exome AF: 0.000291

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.000220

Gnomad4 FIN exome AF: 0.000393

Gnomad4 NFE exome AF: 0.00104

Gnomad4 OTH exome AF: 0.000414

GnomAD4 genome AF: 0.000533 AC: 81 AN: 152082 Hom.: 0 Cov.: 32 AF XY: 0.000471 AC XY: 35 AN XY: 74278

Gnomad4 AFR AF: 0.000169

Gnomad4 AMR AF: 0.000328

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.000985

Gnomad4 OTH AF: 0.000961

Alfa AF: 0.000747 Hom.: 0

Bravo AF: 0.000446

EpiCase AF: 0.00109

EpiControl AF: 0.000889

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:1 Benign:8

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Hyperkalemic periodic paralysis Benign:2

Likely benign, criteria provided, single submitter	clinical testing	Invitae	Jan 26, 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. -

not provided Benign:2

Likely benign, criteria provided, single submitter	clinical testing	CeGaT Center for Human Genetics Tuebingen	Jan 01, 2024	SCN4A: BP4, BP7 -
Likely benign, criteria provided, single submitter	clinical testing	GeneDx	Oct 15, 2021	- -

Congenital myasthenic syndrome 16 Uncertain:1

Uncertain significance, 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, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -

not specified Benign:1

Benign, criteria provided, single submitter

clinical testing

Athena Diagnostics

Apr 27, 2017

- -

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. -

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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.80
Cadd	Benign	5.4
Dann	Benign	0.65

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: rs149726115; hg19: chr17-62045420; COSMIC: COSV71125954; COSMIC: COSV71125954;