2-165386976-G-A

Variant names:

• chr2-165386976-G-A
• rs1057521747
• NM_001040142.2:c.4782G>A

Variant summary

Our verdict is Pathogenic. The variant received 10 ACMG points: 10P and 0B. PVS1 PM2

The NM_001040142.2(SCN2A):​c.4782G>A​(p.Trp1594*) variant causes a stop gained change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar.

• Frequency: Genomes: not found (cov: 32)
• Consequence: SCN2A NM_001040142.2 stop_gained
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 10.0
• Publications: 0 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 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

ACMG classification

Our verdict: Pathogenic. The variant received 10 ACMG points.

• PVS1: Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant is located in the 3'-most 50 bp of the penultimate exon, not predicted to undergo nonsense mediated mRNA decay. There are 124 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
SCN2A	NM_001040142.2	c.4782G>A	p.Trp1594*	stop_gained	Exon 26 of 27	ENST00000375437.7	NP_001035232.1
SCN2A	NM_001371246.1	c.4782G>A	p.Trp1594*	stop_gained	Exon 26 of 27	ENST00000631182.3	NP_001358175.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
SCN2A	ENST00000375437.7	c.4782G>A	p.Trp1594*	stop_gained	Exon 26 of 27	5	NM_001040142.2	ENSP00000364586.2
SCN2A	ENST00000631182.3	c.4782G>A	p.Trp1594*	stop_gained	Exon 26 of 27	5	NM_001371246.1	ENSP00000486885.1
SCN2A	ENST00000283256.10	c.4782G>A	p.Trp1594*	stop_gained	Exon 26 of 27	1		ENSP00000283256.6

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

Alfa AF: 0.000129 Hom.: 0

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Pathogenic	0.66
CADD	Pathogenic	48
DANN	Uncertain	1.0
Eigen	Pathogenic	1.0
Eigen_PC	Pathogenic	0.89
FATHMM_MKL	Pathogenic	0.99	D
PhyloP100		10
Vest4		0.93
GERP RS		5.2
Mutation Taster		=2/198	disease causing

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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: rs1057521747; hg19: chr2-166243486; COSMIC: COSV51836091;