rs1553568927

Variant names:

• chr2-165313919-G-GA
• rs1553568927
• NM_001040142.2:c.1198dupA

Variant summary

Our verdict is Pathogenic. Variant got 12 ACMG points: 12P and 0B. PVS1 PM2 PP5_Moderate

The NM_001040142.2(SCN2A):​c.1198dupA​(p.Thr400AsnfsTer30) variant causes a frameshift change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Pathogenic (★). Variant results in nonsense mediated mRNA decay.

• Frequency: Genomes: not found (cov: 32)
• Consequence: SCN2A NM_001040142.2 frameshift
• Clinical Significance: Pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 9.32

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]

ACMG classification

Verdict is Pathogenic. Variant got 12 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 2-165313919-G-GA is Pathogenic according to our data. Variant chr2-165313919-G-GA is described in ClinVar as [Pathogenic]. Clinvar id is 410976.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
SCN2A	NM_001040142.2	c.1198dupA	p.Thr400AsnfsTer30	frameshift_variant	Exon 10 of 27	ENST00000375437.7	NP_001035232.1
SCN2A	NM_001371246.1	c.1198dupA	p.Thr400AsnfsTer30	frameshift_variant	Exon 10 of 27	ENST00000631182.3	NP_001358175.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
SCN2A	ENST00000375437.7	c.1198dupA	p.Thr400AsnfsTer30	frameshift_variant	Exon 10 of 27	5	NM_001040142.2	ENSP00000364586.2
SCN2A	ENST00000631182.3	c.1198dupA	p.Thr400AsnfsTer30	frameshift_variant	Exon 10 of 27	5	NM_001371246.1	ENSP00000486885.1
SCN2A	ENST00000283256.10	c.1198dupA	p.Thr400AsnfsTer30	frameshift_variant	Exon 10 of 27	1		ENSP00000283256.6
SCN2A	ENST00000424833.5	c.1198dupA	p.Thr400AsnfsTer30	frameshift_variant	Exon 10 of 11	1		ENSP00000406454.2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 33

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

Seizures, benign familial infantile, 3;C3150987:Developmental and epileptic encephalopathy, 11 Pathogenic:1

Oct 20, 2019

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change creates a premature translational stop signal (p.Thr400Asnfs*30) in the SCN2A gene. It is expected to result in an absent or disrupted protein product. For these reasons, this variant has been classified as Pathogenic. Loss-of-function variants in SCN2A are known to be pathogenic (PMID: 22495306, 23020937, 24650168). This variant has not been reported in the literature in individuals with SCN2A-related conditions. ClinVar contains an entry for this variant (Variation ID: 410976). This variant is not present in population databases (ExAC no frequency). -

Computational scores

Source: dbNSFP v4.3

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: rs1553568927; hg19: chr2-166170429;