2-165367225-C-T
Variant summary
Our verdict is Likely benign. The variant received -3 ACMG points: 1P and 4B. PP2BS2
The NM_001040142.2(SCN2A):c.3529C>T(p.Arg1177Trp) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000104 in 1,613,930 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R1177Q) has been classified as Likely benign.
Frequency
Consequence
NM_001040142.2 missense
Scores
Clinical Significance
Conservation
Publications
- complex neurodevelopmental disorderInheritance: AD Classification: DEFINITIVE Submitted by: ClinGen, Illumina
- developmental and epileptic encephalopathy, 11Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: G2P, Ambry Genetics, Labcorp Genetics (formerly Invitae)
- intellectual disabilityInheritance: AD Classification: DEFINITIVE Submitted by: G2P
- episodic ataxia, type 9Inheritance: AD Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae)
- seizures, benign familial infantile, 3Inheritance: AD Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics
- benign familial infantile epilepsyInheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
- benign familial neonatal-infantile seizuresInheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
- Dravet syndromeInheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
- genetic developmental and epileptic encephalopathyInheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
- infantile spasmsInheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
- malignant migrating partial seizures of infancyInheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
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ACMG classification
Our verdict: Likely_benign. The variant received -3 ACMG points.
Transcripts
RefSeq
Ensembl
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | TSL | MANE | Protein | Appris | UniProt |
|---|---|---|---|---|---|---|---|---|---|---|
| SCN2A | ENST00000375437.7 | c.3529C>T | p.Arg1177Trp | missense_variant | Exon 19 of 27 | 5 | NM_001040142.2 | ENSP00000364586.2 | ||
| SCN2A | ENST00000631182.3 | c.3529C>T | p.Arg1177Trp | missense_variant | Exon 19 of 27 | 5 | NM_001371246.1 | ENSP00000486885.1 | ||
| SCN2A | ENST00000283256.10 | c.3529C>T | p.Arg1177Trp | missense_variant | Exon 19 of 27 | 1 | ENSP00000283256.6 |
Frequencies
GnomAD3 genomes AF: 0.0000658 AC: 10AN: 152036Hom.: 0 Cov.: 32 show subpopulations
GnomAD2 exomes AF: 0.0000318 AC: 8AN: 251246 AF XY: 0.0000515 show subpopulations
GnomAD4 exome AF: 0.000108 AC: 158AN: 1461776Hom.: 0 Cov.: 31 AF XY: 0.0000990 AC XY: 72AN XY: 727188 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.0000657 AC: 10AN: 152154Hom.: 0 Cov.: 32 AF XY: 0.0000807 AC XY: 6AN XY: 74378 show subpopulations
Age Distribution
ClinVar
Submissions by phenotype
Genetic developmental and epileptic encephalopathy Uncertain:1
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Seizures, benign familial infantile, 3;C3150987:Developmental and epileptic encephalopathy, 11;C5394520:Episodic ataxia, type 9 Uncertain:1
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Seizures, benign familial infantile, 3;C3150987:Developmental and epileptic encephalopathy, 11 Uncertain:1
This sequence change replaces arginine, which is basic and polar, with tryptophan, which is neutral and slightly polar, at codon 1177 of the SCN2A protein (p.Arg1177Trp). This variant is present in population databases (rs115231482, gnomAD 0.005%). This missense change has been observed in individuals with clinical features of SCN2A-related conditions (PMID: 33004838; internal data). ClinVar contains an entry for this variant (Variation ID: 464907). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) has been performed for this missense variant. However, the output from this modeling did not meet the statistical confidence thresholds required to predict the impact of this variant on SCN2A protein function. This variant disrupts the p.Arg1177 amino acid residue in SCN2A. Other variant(s) that disrupt this residue have been observed in individuals with SCN2A-related conditions (internal data), which suggests that this may be a clinically significant amino acid residue. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -
not provided Uncertain:1
Missense variants in this gene are often considered pathogenic (Stenson et al., 2014) In silico analysis supports that this missense variant has a deleterious effect on protein structure/function This substitution is predicted to be in the cytoplasmic loop between the second and third homologous domains Observed in 0.0032% (9/282646 alleles) in large population cohorts (Lek et al., 2016) Observed in heterozygous state in multiple unrelated healthy adult individuals tested at GeneDx Has not been previously published as pathogenic or benign to our knowledge -
Inborn genetic diseases Benign:1
This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at