rs750516202
Variant summary
Our verdict is Uncertain significance. The variant received 2 ACMG points: 6P and 4B. PM1PP2PP3_ModeratePP5BS2
The NM_001165963.4(SCN1A):c.1852C>T(p.Arg618Cys) variant causes a missense change. The variant allele was found at a frequency of 0.0000112 in 1,614,044 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 Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R618S) has been classified as Uncertain significance.
Frequency
Consequence
NM_001165963.4 missense
Scores
Clinical Significance
Conservation
Publications
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ACMG classification
Our verdict: Uncertain_significance. The variant received 2 ACMG points.
Transcripts
RefSeq
Ensembl
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | TSL | MANE | Protein | Appris | UniProt |
|---|---|---|---|---|---|---|---|---|---|---|
| SCN1A | ENST00000674923.1 | c.1852C>T | p.Arg618Cys | missense_variant | Exon 14 of 29 | NM_001165963.4 | ENSP00000501589.1 | |||
| SCN1A | ENST00000303395.9 | c.1852C>T | p.Arg618Cys | missense_variant | Exon 13 of 28 | 5 | ENSP00000303540.4 | |||
| SCN1A | ENST00000375405.7 | c.1852C>T | p.Arg618Cys | missense_variant | Exon 11 of 26 | 5 | ENSP00000364554.3 | |||
| SCN1A | ENST00000409050.2 | c.1852C>T | p.Arg618Cys | missense_variant | Exon 13 of 28 | 5 | ENSP00000386312.1 |
Frequencies
GnomAD3 genomes AF: 0.00000657 AC: 1AN: 152160Hom.: 0 Cov.: 32 show subpopulations
GnomAD2 exomes AF: 0.00000398 AC: 1AN: 251358 AF XY: 0.00000736 show subpopulations
GnomAD4 exome AF: 0.0000116 AC: 17AN: 1461884Hom.: 0 Cov.: 32 AF XY: 0.0000138 AC XY: 10AN XY: 727242 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.00000657 AC: 1AN: 152160Hom.: 0 Cov.: 32 AF XY: 0.0000135 AC XY: 1AN XY: 74328 show subpopulations
ClinVar
Submissions by phenotype
not provided Uncertain:2
Observed in the homozygous state in siblings with febrile seizures and focal seizures whose parents were unaffected (PMID: 25795284); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; This variant is associated with the following publications: (PMID: 35571373, 35074891, 35813073, 39200163, 25795284, 37006128) -
SCN1A: PM2, PP2 -
Developmental and epileptic encephalopathy Pathogenic:1
This sequence change replaces arginine, which is basic and polar, with cysteine, which is neutral and slightly polar, at codon 618 of the SCN1A protein (p.Arg618Cys). This variant is present in population databases (rs750516202, gnomAD 0.0009%). This missense change has been observed in individuals with generalized epilepsy with febrile seizures plus (PMID: 35571373; Invitae). This variant was reported in the homozygous state in two siblings affected with febrile seizures plus focal seizures and in the heterozygous state in the unaffected carrier parents (PMID: 25795284). Although SCN1A-related epilepsy is typically dominant, the authors propose that this variant may cause a recessive form of the disorder. ClinVar contains an entry for this variant (Variation ID: 220200). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is expected to disrupt SCN1A protein function with a positive predictive value of 95%. For these reasons, this variant has been classified as Pathogenic. -
Inborn genetic diseases Uncertain:1
The c.1852C>T (p.R618C) alteration is located in exon 11 (coding exon 11) of the SCN1A gene. This alteration results from a C to T substitution at nucleotide position 1852, causing the arginine (R) at amino acid position 618 to be replaced by a cysteine (C). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at