Genetic Variant SCN1A:p.Gly1586Ala (chr2-165994241-C-G) – ACMG Classification: Likely_pathogenic (7 pts)

Variant summary

Our verdict is Likely pathogenic. The variant received 7 ACMG points: 7P and 0B. PM1PM2PM5PP2

The NM_001165963.4(SCN1A):c.4757G>C(p.Gly1586Ala) variant causes a missense change. The variant allele was found at a frequency of 0.00000658 in 152,024 control chromosomes in the GnomAD database, with no homozygous occurrence. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. G1586E) has been classified as Pathogenic.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)

Consequence

SCN1A
NM_001165963.4 missense

Scores

Clinical Significance

Not reported in ClinVar

Conservation

PhyloP100: 4.79

Publications

8 publications found

Variant links:

Genes affected

SCN1A (HGNC:10585): (sodium voltage-gated channel alpha subunit 1) Voltage-dependent sodium channels are heteromeric complexes that regulate sodium exchange between intracellular and extracellular spaces and are essential for the generation and propagation of action potentials in muscle cells and neurons. Each sodium channel is composed of a large pore-forming, glycosylated alpha subunit and two smaller beta subunits. This gene encodes a sodium channel alpha subunit, which has four homologous domains, each of which contains six transmembrane regions. Allelic variants of this gene are associated with generalized epilepsy with febrile seizures and epileptic encephalopathy. Alternative splicing results in multiple transcript variants. The RefSeq Project has decided to create four representative RefSeq records. Three of the transcript variants are supported by experimental evidence and the fourth contains alternate 5' untranslated exons, the exact combination of which have not been experimentally confirmed for the full-length transcript. [provided by RefSeq, Oct 2015]

SCN1A links:

SCN1A-AS1 (HGNC:54069): (SCN1A and SCN9A antisense RNA 1)

SCN1A-AS1 links:

LOC102724058 (HGNC:):

LOC102724058 links:

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ACMG classification

Classification was made for transcript

Our verdict: Likely_pathogenic. The variant received 7 ACMG points.

PM1

In a hotspot region, there are 10 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 13 uncertain in NM_001165963.4

PM2

Very rare variant in population databases, with high coverage;

PM5

Other missense variant is known to change same aminoacid residue: Variant chr2-165994241-C-T is described in ClinVar as Pathogenic. ClinVar VariationId is 68637.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

PP2

Missense variant in the SCN1A gene, where missense mutations are typically associated with disease (based on misZ statistic). The gene has 848 curated pathogenic missense variants (we use a threshold of 10). The gene has 89 curated benign missense variants. Gene score misZ: 5.2206 (above the threshold of 3.09). Trascript score misZ: 7.6022 (above the threshold of 3.09). GenCC associations: The gene is linked to familial or sporadic hemiplegic migraine, myoclonic-astatic epilepsy, arthrogryposis, Dravet syndrome, malignant migrating partial seizures of infancy, generalized epilepsy with febrile seizures plus, type 2, migraine, familial hemiplegic, 3, developmental and epileptic encephalopathy, 6A, familial hemiplegic migraine, generalized epilepsy with febrile seizures plus, genetic developmental and epileptic encephalopathy, Lennox-Gastaut syndrome.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_001165963.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
SCN1A	NM_001165963.4	MANE Select	c.4757G>C	p.Gly1586Ala	missense	Exon 28 of 29	NP_001159435.1	P35498-1
SCN1A	NM_001202435.3		c.4757G>C	p.Gly1586Ala	missense	Exon 27 of 28	NP_001189364.1	P35498-1
SCN1A	NM_001353948.2		c.4757G>C	p.Gly1586Ala	missense	Exon 26 of 27	NP_001340877.1	P35498-1

Ensembl Transcripts

Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
SCN1A	ENST00000674923.1	MANE Select	c.4757G>C	p.Gly1586Ala	missense	Exon 28 of 29	ENSP00000501589.1	P35498-1
SCN1A	ENST00000303395.9	TSL:5	c.4757G>C	p.Gly1586Ala	missense	Exon 27 of 28	ENSP00000303540.4	P35498-1
SCN1A	ENST00000375405.7	TSL:5	c.4724G>C	p.Gly1575Ala	missense	Exon 25 of 26	ENSP00000364554.3	P35498-2

Frequencies

GnomAD3 genomes

AF:

0.00000658

AC:

AN:

151906

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.000207

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.00

Gnomad OTH

AF:

0.00

GnomAD4 exome

Cov.:

GnomAD4 genome

AF:

0.00000658

AC:

AN:

152024

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

74296

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

41532

American (AMR)

AF:

0.00

AC:

AN:

15232

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3466

East Asian (EAS)

AF:

0.00

AC:

AN:

5140

South Asian (SAS)

AF:

0.000207

AC:

AN:

4820

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10602

Middle Eastern (MID)

AF:

0.00

AC:

AN:

294

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

67914

Other (OTH)

AF:

0.00

AC:

AN:

2112

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.425

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

ExAC

AF:

0.00000824

AC:

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.13

BayesDel_addAF

Pathogenic

0.23

BayesDel_noAF

Uncertain

0.10

CADD

Uncertain

(source)

DANN

Uncertain

1.0

DEOGEN2

Pathogenic

0.90

Eigen

Uncertain

0.45

Eigen_PC

Uncertain

0.55

FATHMM_MKL

Uncertain

0.96

LIST_S2

Uncertain

0.89

M_CAP

Pathogenic

0.40

MetaRNN

Uncertain

0.74

MetaSVM

Pathogenic

0.95

MutationAssessor

Benign

0.020

PhyloP100

4.8

PrimateAI

Pathogenic

0.83

PROVEAN

Uncertain

-3.4

REVEL

Pathogenic

0.67

Sift

Benign

0.080

Sift4G

Benign

0.57

Polyphen

0.91

Vest4

0.63

MutPred

0.55

Loss of methylation at K1591 (P = 0.102)

MVP

0.92

MPC

1.8

ClinPred

0.97

GERP RS

5.9

Varity_R

0.43

gMVP

0.93

Mutation Taster

=5/95

disease causing

(source)

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.040

Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Variant Effect in Transcripts

RefSeq Transcripts

Ensembl Transcripts

Frequencies

ClinVar

Computational scores

Splicing

Publications

Other links and lift over