2-165294040-A-T

Variant names:

• chr2-165294040-A-T
• rs76193610
• ENST00000283256.10:c.-147A>T

Variant summary

Our verdict is Likely benign. The variant received -4 ACMG points: 0P and 4B. BP4_Strong

The ENST00000283256.10(SCN2A):​c.-147A>T 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 (GnomAdExome4), which may indicate mosaicism or somatic mutations in the reference population data. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: 𝑓 0.00037 (0 hom., cov: 20)
  • Exomes 𝑓: 0.00059 (0 hom.)
  • Failed GnomAD Quality Control
• Consequence: SCN2A ENST00000283256.10 5_prime_UTR
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: -0.420
• 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: Likely_benign. The variant received -4 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.91).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
SCN2A	NM_001040142.2	c.-51-1733A>T		intron_variant	Intron 1 of 26	ENST00000375437.7	NP_001035232.1
SCN2A	NM_001371246.1	c.-51-1733A>T		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.-147A>T		5_prime_UTR_variant	Exon 1 of 27	1		ENSP00000283256.6
SCN2A	ENST00000375437.7	c.-51-1733A>T		intron_variant	Intron 1 of 26	5	NM_001040142.2	ENSP00000364586.2
SCN2A	ENST00000631182.3	c.-51-1733A>T		intron_variant	Intron 1 of 26	5	NM_001371246.1	ENSP00000486885.1
SCN2A	ENST00000424833.5	c.-51-1733A>T		intron_variant	Intron 1 of 10	1		ENSP00000406454.2

Frequencies

GnomAD3 genomes AF: 0.000367 AC: 38 AN: 103596 Hom.: 0 Cov.: 20

Gnomad AFR AF: 0.000434

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.000227

Gnomad ASJ AF: 0.000380

Gnomad EAS AF: 0.000302

Gnomad SAS AF: 0.000683

Gnomad FIN AF: 0.00202

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.000247

Gnomad OTH AF: 0.00

GnomAD4 exome AF: 0.000586 AC: 308 AN: 525172 Hom.: 0 Cov.: 8 AF XY: 0.000565 AC XY: 138 AN XY: 244194

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

African (AFR) AF: 0.00113 AC: 11 AN: 9756

American (AMR) AF: 0.00152 AC: 1 AN: 658

Ashkenazi Jewish (ASJ) AF: 0.000980 AC: 3 AN: 3060

East Asian (EAS) AF: 0.00 AC: 0 AN: 2426

South Asian (SAS) AF: 0.000676 AC: 7 AN: 10348

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

Middle Eastern (MID) AF: 0.00110 AC: 1 AN: 910

European-Non Finnish (NFE) AF: 0.000551 AC: 265 AN: 480650

Other (OTH) AF: 0.00116 AC: 20 AN: 17182

⚠️ 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 Data not reliable, filtered out with message: AS_VQSR AF: 0.000367 AC: 38 AN: 103632 Hom.: 0 Cov.: 20 AF XY: 0.000438 AC XY: 21 AN XY: 47902

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

African (AFR) AF: 0.000433 AC: 12 AN: 27702

American (AMR) AF: 0.000227 AC: 2 AN: 8822

Ashkenazi Jewish (ASJ) AF: 0.000380 AC: 1 AN: 2632

East Asian (EAS) AF: 0.000302 AC: 1 AN: 3308

South Asian (SAS) AF: 0.000684 AC: 2 AN: 2922

European-Finnish (FIN) AF: 0.00202 AC: 7 AN: 3458

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 176

European-Non Finnish (NFE) AF: 0.000247 AC: 13 AN: 52536

Other (OTH) AF: 0.00 AC: 0 AN: 1346

⚠️ 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.

Alfa AF: 0.00 Hom.: 0

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Seizures, benign familial infantile, 3 Uncertain:1

Apr 27, 2017

Illumina Laboratory Services, Illumina

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant was observed as part of a predisposition screen in an ostensibly healthy population. A literature search was performed for the gene, cDNA change, and amino acid change (where applicable). No publications were found based on this search. Allele frequency data from public databases did not allow this variant to be ruled in or out of causing disease. Therefore, this variant is classified as a variant of unknown significance. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.91
CADD	Benign	1.2
DANN	Benign	0.34
PhyloP100		-0.42
PromoterAI		-0.052	Neutral

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: rs76193610; hg19: chr2-166150550;