17-63938943-T-C

Variant names:

• chr17-63938943-T-C
• rs79003915
• NM_000334.4:c.*1828A>G

Variant summary

Our verdict is Benign. Variant got -14 ACMG points: 0P and 14B. BP4_Strong BP6_Moderate BS1 BS2

The NM_000334.4(SCN4A):​c.*1828A>G variant causes a 3 prime UTR change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00251 in 153,202 control chromosomes in the GnomAD database, including 5 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★).

• Frequency:
  • Genomes: 𝑓 0.0025 (5 hom., cov: 33)
  • Exomes 𝑓: 0.0093 (0 hom.)
• Consequence: SCN4A NM_000334.4 3_prime_UTR
• Clinical Significance: Benign/Likely benign criteria provided, single submitter B:5
• Conservation: PhyloP100: 0.437

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 -14 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.84).
• BP6: Variant 17-63938943-T-C is Benign according to our data. Variant chr17-63938943-T-C is described in ClinVar as [Likely_benign]. Clinvar id is 324472.Status of the report is criteria_provided_single_submitter, 1 stars.
• BS1: Variant frequency is greater than expected in population eas. gnomad4 allele frequency = 0.00246 (374/152128) while in subpopulation EAS AF= 0.0122 (63/5166). AF 95% confidence interval is 0.00978. There are 5 homozygotes in gnomad4. There are 252 alleles in male gnomad4 subpopulation. Median coverage is 33. This position pass quality control queck.
• BS2: High Homozygotes in GnomAd4 at 5 AD,AR gene

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
SCN4A	NM_000334.4	c.*1828A>G		3_prime_UTR_variant	Exon 24 of 24	ENST00000435607.3	NP_000325.4

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
SCN4A	ENST00000435607	c.*1828A>G		3_prime_UTR_variant	Exon 24 of 24	1	NM_000334.4	ENSP00000396320.1

Frequencies

GnomAD3 genomes AF: 0.00247 AC: 376 AN: 152010 Hom.: 5 Cov.: 33

Gnomad AFR AF: 0.0000483

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.000393

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.0122

Gnomad SAS AF: 0.000621

Gnomad FIN AF: 0.0230

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.000780

Gnomad OTH AF: 0.00239

GnomAD4 exome AF: 0.00931 AC: 10 AN: 1074 Hom.: 0 Cov.: 0 AF XY: 0.00737 AC XY: 5 AN XY: 678

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: 0.0198

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome AF: 0.00246 AC: 374 AN: 152128 Hom.: 5 Cov.: 33 AF XY: 0.00339 AC XY: 252 AN XY: 74372

Gnomad4 AFR AF: 0.0000482

Gnomad4 AMR AF: 0.000392

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.0122

Gnomad4 SAS AF: 0.000415

Gnomad4 FIN AF: 0.0230

Gnomad4 NFE AF: 0.000780

Gnomad4 OTH AF: 0.00190

Alfa AF: 0.00157 Hom.: 0

Bravo AF: 0.000608

Asia WGS AF: 0.00693 AC: 24 AN: 3478

ClinVar

Significance: Benign/Likely benign

Submissions summary: Benign:5

Revision: criteria provided, single submitter

Submissions by phenotype

Hypokalemic periodic paralysis, type 2 Benign:1

Jan 12, 2018

Illumina Laboratory Services, Illumina

Significance: Benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

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

Jan 12, 2018

Illumina Laboratory Services, Illumina

Significance: Benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

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. -

Hyperkalemic periodic paralysis Benign:1

Jan 12, 2018

Illumina Laboratory Services, Illumina

Significance: Benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

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

Jan 12, 2018

Illumina Laboratory Services, Illumina

Significance: Benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

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

Jan 12, 2018

Illumina Laboratory Services, Illumina

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

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 likely benign is not then subjected to further curation. The score for this variant resulted in a classification of likely benign for this disease. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.84
CADD	Benign	1.3
DANN	Benign	0.50

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: rs79003915; hg19: chr17-62016303;