rs1553591763

Positions:

• chr2-165370176-A-T

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM2 PP2 PP3

The NM_001040142.2(SCN2A):​c.3726A>T​(p.Leu1242Phe) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,461,818 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: SCN2A NM_001040142.2 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 2.94

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 (HGNC:):

ACMG classification

Verdict is Uncertain_significance. Variant got 4 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant in gene, where missense usually causes diseases (based on misZ statistic), SCN2A. . Trascript score misZ 8.7114 (greater than threshold 3.09). GenCC has associacion of gene with seizures, benign familial infantile, 3, Dravet syndrome, benign familial neonatal-infantile seizures, malignant migrating partial seizures of infancy, complex neurodevelopmental disorder, developmental and epileptic encephalopathy, 11, developmental and epileptic encephalopathy, West syndrome, benign familial infantile epilepsy, episodic ataxia, type 9.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.815

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
SCN2A	NM_001040142.2	c.3726A>T	p.Leu1242Phe	missense_variant	20/27	ENST00000375437.7	NP_001035232.1
SCN2A	NM_001371246.1	c.3726A>T	p.Leu1242Phe	missense_variant	20/27	ENST00000631182.3	NP_001358175.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
SCN2A	ENST00000375437.7	c.3726A>T	p.Leu1242Phe	missense_variant	20/27	5	NM_001040142.2	ENSP00000364586.2
SCN2A	ENST00000631182.3	c.3726A>T	p.Leu1242Phe	missense_variant	20/27	5	NM_001371246.1	ENSP00000486885.1
SCN2A	ENST00000283256.10	c.3726A>T	p.Leu1242Phe	missense_variant	20/27	1		ENSP00000283256.6

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1461818 Hom.: 0 Cov.: 31 AF XY: 0.00000275 AC XY: 2 AN XY: 727210

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000180

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Inborn genetic diseases Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Jun 09, 2016

- -

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

GeneDx

Jun 07, 2017

A variant of uncertain significance has been identified in the SCN2A gene. The L1242F variant has not been published as a pathogenic variant, nor has it been reported as a benign variant to our knowledge. The L1242F variant is not observed in large population cohorts (Lek et al., 2016; 1000 Genomes Consortium et al., 2015; Exome Variant Server). The L1242F variant is a conservative amino acid substitution, which is not likely to impact secondary protein structure as these residues share similar properties. However this substitution alters a conserved position predicted to be within the transmembrane segment S2 of the third homologous domain. Additionally, in silico analysis predicts this variant is probably damaging to the protein structure/function. Therefore, based on the currently available information, it is unclear whether this variant is a pathogenic variant or a rare benign variant. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.98
BayesDel_addAF	Pathogenic	0.46	D
BayesDel_noAF	Pathogenic	0.42
CADD	Benign	20
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.97	D;.;T;.;D;D;.
Eigen	Uncertain	0.32
Eigen_PC	Benign	0.18
FATHMM_MKL	Uncertain	0.82	D
LIST_S2	Pathogenic	0.99	D;.;D;.;.;.;D
M_CAP	Pathogenic	0.66	D
MetaRNN	Pathogenic	0.82	D;D;D;D;D;D;D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Pathogenic	4.0	H;H;.;H;H;H;H
PrimateAI	Pathogenic	0.89	D
PROVEAN	Uncertain	-3.8	D;.;.;.;.;D;D
REVEL	Pathogenic	0.80
Sift	Pathogenic	0.0	D;.;.;.;.;D;D
Sift4G	Pathogenic	0.0010	D;.;.;D;.;D;D
Polyphen		1.0	D;D;.;D;D;D;D
Vest4		0.85
MutPred		0.36		Gain of loop (P = 0.069);Gain of loop (P = 0.069);.;Gain of loop (P = 0.069);Gain of loop (P = 0.069);Gain of loop (P = 0.069);Gain of loop (P = 0.069);
MVP		0.98
ClinPred		1.0	D
GERP RS		-0.74
Varity_R		0.88
gMVP		0.99

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

Publications

LitVar

Other links and lift over

dbSNP: rs1553591763; hg19: chr2-166226686;