2-165294040-A-AAAAT

Variant names:

• chr2-165294040-A-AAAAT
• rs780674346
• ENST00000283256.10:c.-147_-146insAAAT

Variant summary

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

The ENST00000283256.10(SCN2A):​c.-147_-146insAAAT variant causes a 5 prime UTR change involving the alteration of a non-conserved nucleotide. There is a variant allele frequency bias in the population database for this variant (GnomAd4), which may indicate mosaicism or somatic mutations in the reference population data. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: 𝑓 0.000087 (0 hom., cov: 11)
  • Exomes 𝑓: 0.0000057 (0 hom.)
• Consequence: SCN2A ENST00000283256.10 5_prime_UTR
• Clinical Significance: Uncertain significance criteria provided, single submitter U:2
• Conservation: PhyloP100: 0.275
• Publications: 1 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: Uncertain_significance. The variant received 0 ACMG points.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
SCN2A	NM_001040142.2	c.-51-1733_-51-1732insAAAT		intron_variant	Intron 1 of 26	ENST00000375437.7	NP_001035232.1
SCN2A	NM_001371246.1	c.-51-1733_-51-1732insAAAT		intron_variant	Intron 1 of 26	ENST00000631182.3	NP_001358175.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
SCN2A	ENST00000283256.10	c.-147_-146insAAAT		5_prime_UTR_variant	Exon 1 of 27	1		ENSP00000283256.6
SCN2A	ENST00000375437.7	c.-51-1733_-51-1732insAAAT		intron_variant	Intron 1 of 26	5	NM_001040142.2	ENSP00000364586.2
SCN2A	ENST00000631182.3	c.-51-1733_-51-1732insAAAT		intron_variant	Intron 1 of 26	5	NM_001371246.1	ENSP00000486885.1
SCN2A	ENST00000424833.5	c.-51-1733_-51-1732insAAAT		intron_variant	Intron 1 of 10	1		ENSP00000406454.2

Frequencies

GnomAD3 genomes AF: 0.0000868 AC: 9 AN: 103632 Hom.: 0 Cov.: 11

Gnomad AFR AF: 0.000108

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.000302

Gnomad SAS AF: 0.000341

Gnomad FIN AF: 0.000289

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000571

Gnomad OTH AF: 0.00

GnomAD4 exome AF: 0.00000570 AC: 3 AN: 526710 Hom.: 0 Cov.: 0 AF XY: 0.00000817 AC XY: 2 AN XY: 244876

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.00 AC: 0 AN: 9786

American (AMR) AF: 0.00 AC: 0 AN: 658

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3078

East Asian (EAS) AF: 0.00 AC: 0 AN: 2428

South Asian (SAS) AF: 0.00 AC: 0 AN: 10388

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 182

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 912

European-Non Finnish (NFE) AF: 0.00000622 AC: 3 AN: 482042

Other (OTH) AF: 0.00 AC: 0 AN: 17236

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0.000000), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome AF: 0.0000868 AC: 9 AN: 103668 Hom.: 0 Cov.: 11 AF XY: 0.000104 AC XY: 5 AN XY: 47918

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.000108 AC: 3 AN: 27708

American (AMR) AF: 0.00 AC: 0 AN: 8822

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 2632

East Asian (EAS) AF: 0.000302 AC: 1 AN: 3310

South Asian (SAS) AF: 0.000342 AC: 1 AN: 2928

European-Finnish (FIN) AF: 0.000289 AC: 1 AN: 3460

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 178

European-Non Finnish (NFE) AF: 0.0000571 AC: 3 AN: 52550

Other (OTH) AF: 0.00 AC: 0 AN: 1348

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5. (p-value = 0.000000), which strongly suggests a high chance of mosaicism in these individuals.

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, single submitter

Submissions by phenotype

Early Infantile Epileptic Encephalopathy, Autosomal Dominant Uncertain:1

Jun 14, 2016

Illumina Laboratory Services, Illumina

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Seizures, benign familial infantile, 3 Uncertain:1

Jun 14, 2016

Illumina Laboratory Services, Illumina

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
PhyloP100		0.28

Splicing

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

Other links and lift over

dbSNP: rs780674346; hg19: chr2-166150550;