chr2-165315571-C-G

Variant summary

Our verdict is Uncertain significance. The variant received 5 ACMG points: 5P and 0B. PM2PP2PP3_Moderate

The NM_001040142.2(SCN2A):​c.1484C>G​(p.Ser495Cys) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,461,770 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. S495Y) has been classified as Uncertain significance.

Frequency

Genomes: not found (cov: 33)
Exomes 𝑓: 0.0000014 ( 0 hom. )

Consequence

SCN2A
NM_001040142.2 missense

Scores

12
6
1

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 7.57

Publications

2 publications found
Variant links:
Genes affected
SCN2A (HGNC:10588): (sodium voltage-gated channel alpha subunit 2) Voltage-gated sodium channels are transmembrane glycoprotein complexes composed of a large alpha subunit with four repeat domains, each of which is composed of six membrane-spanning segments, and one or more regulatory beta subunits. Voltage-gated sodium channels function in the generation and propagation of action potentials in neurons and muscle. This gene encodes one member of the sodium channel alpha subunit gene family. Allelic variants of this gene are associated with seizure disorders and autism spectrum disorder. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Nov 2016]
SCN2A Gene-Disease associations (from GenCC):
  • complex neurodevelopmental disorder
    Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen, Illumina
  • developmental and epileptic encephalopathy, 11
    Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: G2P, Ambry Genetics, Labcorp Genetics (formerly Invitae)
  • intellectual disability
    Inheritance: AD Classification: DEFINITIVE Submitted by: G2P
  • episodic ataxia, type 9
    Inheritance: AD Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae)
  • seizures, benign familial infantile, 3
    Inheritance: AD Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics
  • benign familial infantile epilepsy
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
  • benign familial neonatal-infantile seizures
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
  • Dravet syndrome
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
  • genetic developmental and epileptic encephalopathy
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
  • infantile spasms
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
  • malignant migrating partial seizures of infancy
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 5 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
PP2
Missense variant in the SCN2A gene, where missense mutations are typically associated with disease (based on misZ statistic). The gene has 362 curated pathogenic missense variants (we use a threshold of 10). The gene has 36 curated benign missense variants. Trascript score misZ: 8.7114 (above the threshold of 3.09). GenCC associations: The gene is linked to genetic developmental and epileptic encephalopathy, episodic ataxia, type 9, seizures, benign familial infantile, 3, complex neurodevelopmental disorder, benign familial neonatal-infantile seizures, Dravet syndrome, infantile spasms, developmental and epileptic encephalopathy, 11, intellectual disability, benign familial infantile epilepsy, malignant migrating partial seizures of infancy.
PP3
MetaRNN computational evidence supports a deleterious effect, 0.885

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
SCN2ANM_001040142.2 linkc.1484C>G p.Ser495Cys missense_variant Exon 11 of 27 ENST00000375437.7 NP_001035232.1 Q99250-1
SCN2ANM_001371246.1 linkc.1484C>G p.Ser495Cys missense_variant Exon 11 of 27 ENST00000631182.3 NP_001358175.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
SCN2AENST00000375437.7 linkc.1484C>G p.Ser495Cys missense_variant Exon 11 of 27 5 NM_001040142.2 ENSP00000364586.2 Q99250-1
SCN2AENST00000631182.3 linkc.1484C>G p.Ser495Cys missense_variant Exon 11 of 27 5 NM_001371246.1 ENSP00000486885.1 Q99250-2
SCN2AENST00000283256.10 linkc.1484C>G p.Ser495Cys missense_variant Exon 11 of 27 1 ENSP00000283256.6 Q99250-1
SCN2AENST00000424833.5 linkc.1484C>G p.Ser495Cys missense_variant Exon 11 of 11 1 ENSP00000406454.2 F6U291

Frequencies

GnomAD3 genomes
Cov.:
33
GnomAD2 exomes
AF:
0.00000402
AC:
1
AN:
248470
AF XY:
0.00000743
show subpopulations
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:
0.00000901
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000137
AC:
2
AN:
1461770
Hom.:
0
Cov.:
32
AF XY:
0.00000138
AC XY:
1
AN XY:
727168
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33474
American (AMR)
AF:
0.00
AC:
0
AN:
44712
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26134
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39690
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86258
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53410
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.00000180
AC:
2
AN:
1111934
Other (OTH)
AF:
0.00
AC:
0
AN:
60390
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.450
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
GnomAD4 genome
Cov.:
33
Alfa
AF:
0.0000193
Hom.:
0
ESP6500AA
AF:
0.00
AC:
0
ESP6500EA
AF:
0.000116
AC:
1

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:1
Revision: criteria provided, single submitter
LINK: link

Submissions by phenotype

Seizures, benign familial infantile, 3;C3150987:Developmental and epileptic encephalopathy, 11 Uncertain:1
Oct 22, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces serine, which is neutral and polar, with cysteine, which is neutral and slightly polar, at codon 495 of the SCN2A protein (p.Ser495Cys). This variant is present in population databases (rs140661535, gnomAD 0.0009%). This variant has not been reported in the literature in individuals affected with SCN2A-related conditions. ClinVar contains an entry for this variant (Variation ID: 410981). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) indicates that this missense variant is expected to disrupt SCN2A protein function with a positive predictive value of 95%. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Uncertain
0.37
BayesDel_addAF
Pathogenic
0.28
D
BayesDel_noAF
Pathogenic
0.16
CADD
Uncertain
26
DANN
Uncertain
0.99
DEOGEN2
Pathogenic
0.83
.;D;.;T;.;D;D;.
Eigen
Pathogenic
0.96
Eigen_PC
Pathogenic
0.92
FATHMM_MKL
Pathogenic
0.99
D
LIST_S2
Uncertain
0.93
D;D;.;D;.;.;.;D
M_CAP
Pathogenic
0.73
D
MetaRNN
Pathogenic
0.88
D;D;D;D;D;D;D;D
MetaSVM
Pathogenic
1.1
D
MutationAssessor
Pathogenic
3.3
.;M;M;.;M;M;M;M
PhyloP100
7.6
PrimateAI
Uncertain
0.76
T
PROVEAN
Uncertain
-4.0
D;D;.;.;.;.;D;D
REVEL
Pathogenic
0.73
Sift
Uncertain
0.0050
D;D;.;.;.;.;D;D
Sift4G
Pathogenic
0.0010
D;T;.;.;T;.;T;T
Polyphen
1.0, 0.99
.;D;D;.;D;D;D;D
Vest4
0.68, 0.65, 0.69, 0.68
MVP
0.93
ClinPred
0.97
D
GERP RS
5.9
Varity_R
0.30
gMVP
0.89
Mutation Taster
=33/67
disease causing

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

Other links and lift over

dbSNP: rs140661535; hg19: chr2-166172081; API