rs796053118

Variant names:

• chr2-165344649-T-C
• rs796053118
• NM_001040142.2:c.2657T>C

Variant summary

Our verdict is Likely pathogenic. The variant received 8 ACMG points: 8P and 0B. PM6 PM2_Supporting PS4_Supporting PP3_Moderate PM1

This summary comes from the ClinGen Evidence Repository: The c.2657T>C variant in SCN2A is a missense variant predicted to cause a substitution of leucine by serine at amino acid 886 (p.Leu886Ser). This variant has been identified as a de novo occurrence with unconfirmed parental relationships in 2 individuals with a complex neurodevelopmental disorder (PM6); (PMID:3541799; internal data GeneDx). It has also been identified in an additional proband with a complex neurodevelopmental disorder (PS4_supporting) (internal data, Labcorp). This variant is absent from gnomAD v4.0) (PM2_supporting). The computational predictor REVEL gives a score of 0.971, evidence that correlates with impact to SCN2A function (PP3_moderate). This variant resides within a region of SCN2A that is defined as a mutation hotspot by the ClinGen Epilepsy Sodium Channel VCEP (PM1). In summary, this variant meets the criteria to be classified as Likely Pathogenic for autosomal dominant complex neurodevelopmental disorder based on the ACMG/AMP criteria applied, as specified by the ClinGen Epilepsy Sodium Channel VCEP: (PP3_moderate, PM1, PM6, PM2_supporting, PS4_supporting). Approved March 25, 2025. LINK:https://erepo.genome.network/evrepo/ui/classification/CA317886/MONDO:0100038/068

• Frequency: Genomes: not found (cov: 32)
• Consequence: SCN2A NM_001040142.2 missense
• Clinical Significance: Likely pathogenic reviewed by expert panel P:3 U:1
• Conservation: PhyloP100: 7.91
• Publications: 3 publications found

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, STRONG Submitted by: Illumina, ClinGen, PanelApp Australia
• developmental and epileptic encephalopathy, 11

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: G2P, Labcorp Genetics (formerly Invitae), Ambry Genetics
• 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: Ambry Genetics, Labcorp Genetics (formerly Invitae)
• 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

ACMG classification

Our verdict: Likely_pathogenic. The variant received 8 ACMG points.

• PS4: For more information check the summary or visit ClinGen Evidence Repository.
• PM1: For more information check the summary or visit ClinGen Evidence Repository.
• PM2: For more information check the summary or visit ClinGen Evidence Repository.
• PM6: For more information check the summary or visit ClinGen Evidence Repository.
• PP3: For more information check the summary or visit ClinGen Evidence Repository.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_001040142.2. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	SCN2A	NM_001040142.2	MANE Select	c.2657T>C	p.Leu886Ser	missense	Exon 16 of 27	NP_001035232.1	Q99250-1
	SCN2A	NM_001371246.1	MANE Plus Clinical	c.2657T>C	p.Leu886Ser	missense	Exon 16 of 27	NP_001358175.1	Q99250-2
	SCN2A	NM_001040143.2		c.2657T>C	p.Leu886Ser	missense	Exon 17 of 28	NP_001035233.1	Q99250-2

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	SCN2A	ENST00000375437.7	TSL:5 MANE Select	c.2657T>C	p.Leu886Ser	missense	Exon 16 of 27	ENSP00000364586.2	Q99250-1
	SCN2A	ENST00000631182.3	TSL:5 MANE Plus Clinical	c.2657T>C	p.Leu886Ser	missense	Exon 16 of 27	ENSP00000486885.1	Q99250-2
	SCN2A	ENST00000283256.10	TSL:1	c.2657T>C	p.Leu886Ser	missense	Exon 16 of 27	ENSP00000283256.6	Q99250-1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

ClinVar

ClinVar submissions

Significance: Likely pathogenic

Revision: reviewed by expert panel

Pathogenic	VUS	Benign	Condition
1	-	-	Complex neurodevelopmental disorder (1)
1	-	-	Developmental and epileptic encephalopathy (1)
1	-	-	not provided (1)
-	1	-	Seizures, benign familial infantile, 3;C3150987:Developmental and epileptic encephalopathy, 11 (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.98
BayesDel_addAF	Pathogenic	0.50	D
BayesDel_noAF	Pathogenic	0.48
CADD	Pathogenic	26
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.97	D
Eigen	Pathogenic	0.84
Eigen_PC	Pathogenic	0.80
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.88	D
M_CAP	Pathogenic	0.84	D
MetaRNN	Pathogenic	0.94	D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Pathogenic	2.9	M
PhyloP100		7.9
PrimateAI	Pathogenic	0.90	D
PROVEAN	Pathogenic	-5.8	D
REVEL	Pathogenic	0.97
Sift	Pathogenic	0.0	D
Sift4G	Pathogenic	0.0	D
Polyphen		1.0	D
Vest4		0.93
MutPred		0.69		Gain of catalytic residue at L886 (P = 0.0378)
MVP		0.99
ClinPred		1.0	D
GERP RS		5.5
Varity_R		0.85
gMVP		0.99
Mutation Taster		=1/99	disease causing (ClinVar)

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

Other links and lift over

dbSNP: rs796053118; hg19: chr2-166201159;