rs780175030
Variant summary
Our verdict is Likely benign. The variant received -5 ACMG points: 0P and 5B. BP6BS2
The NM_000748.3(CHRNB2):c.640G>A(p.Glu214Lys) variant causes a missense change. The variant allele was found at a frequency of 0.000018 in 1,613,968 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. E214Q) has been classified as Uncertain significance.
Frequency
Consequence
NM_000748.3 missense
Scores
Clinical Significance
Conservation
Publications
- familial sleep-related hypermotor epilepsyInheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
- autosomal dominant nocturnal frontal lobe epilepsy 3Inheritance: AD Classification: STRONG Submitted by: G2P, Labcorp Genetics (formerly Invitae)
- autosomal dominant nocturnal frontal lobe epilepsyInheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
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ACMG classification
Our verdict: Likely_benign. The variant received -5 ACMG points.
Transcripts
RefSeq
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | MANE | Protein | UniProt |
|---|---|---|---|---|---|---|---|---|
| CHRNB2 | NM_000748.3 | c.640G>A | p.Glu214Lys | missense_variant | Exon 5 of 6 | ENST00000368476.4 | NP_000739.1 | |
| CHRNB2 | XM_017000180.3 | c.130G>A | p.Glu44Lys | missense_variant | Exon 2 of 3 | XP_016855669.1 | ||
| CHRNB2 | XR_001736952.3 | n.907G>A | non_coding_transcript_exon_variant | Exon 5 of 7 |
Ensembl
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | TSL | MANE | Protein | Appris | UniProt |
|---|---|---|---|---|---|---|---|---|---|---|
| CHRNB2 | ENST00000368476.4 | c.640G>A | p.Glu214Lys | missense_variant | Exon 5 of 6 | 1 | NM_000748.3 | ENSP00000357461.3 | ||
| CHRNB2 | ENST00000637900.1 | c.646G>A | p.Glu216Lys | missense_variant | Exon 5 of 6 | 5 | ENSP00000490474.1 | |||
| CHRNB2 | ENST00000636034.1 | n.640G>A | non_coding_transcript_exon_variant | Exon 5 of 9 | 5 | ENSP00000489703.1 |
Frequencies
GnomAD3 genomes AF: 0.0000131 AC: 2AN: 152158Hom.: 0 Cov.: 32 show subpopulations
GnomAD2 exomes AF: 0.0000159 AC: 4AN: 251304 AF XY: 0.0000147 show subpopulations
GnomAD4 exome AF: 0.0000185 AC: 27AN: 1461810Hom.: 0 Cov.: 33 AF XY: 0.0000179 AC XY: 13AN XY: 727198 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.0000131 AC: 2AN: 152158Hom.: 0 Cov.: 32 AF XY: 0.0000135 AC XY: 1AN XY: 74322 show subpopulations
Age Distribution
ClinVar
Submissions by phenotype
Autosomal dominant nocturnal frontal lobe epilepsy Uncertain:1
This sequence change replaces glutamic acid, which is acidic and polar, with lysine, which is basic and polar, at codon 214 of the CHRNB2 protein (p.Glu214Lys). This variant is present in population databases (rs780175030, gnomAD 0.003%). This variant has not been reported in the literature in individuals affected with CHRNB2-related conditions. ClinVar contains an entry for this variant (Variation ID: 205069). 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) indicates that this missense variant is not expected to disrupt CHRNB2 protein function with a negative predictive value of 80%. 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.
Autosomal dominant nocturnal frontal lobe epilepsy 3 Uncertain:1
not provided Uncertain:1
p.Glu214Lys (GAG>AAG): c.640 G>A in exon 5 of the CHRNB2 gene (NM_000748.2). The Glu214Lys missense change has not been published as a mutation, nor has it been reported as a benign polymorphism to our knowledge. It was not observed in approximately 6,500 individuals of European and African American ancestry in the NHLBI Exome Sequencing Project, indicating it is not a common benign variant in these populations. This variant is a non-conservative amino acid substitution of a negatively charged Glutamic acid residue with a positively charged Lysine residue at a position that is conserved through mammals. The Glu214Lys amino acid substitution does not occur within the transmembrane region of the protein, where pathogenic missense mutations have been identified in association with epilepsy (Steinlein et al., 2010). Additionally, in silico analysis is inconsistent with regard to the effect this variant may have on the protein structure/function. Therefore, based on the currently available information, it is unclear whether Glu214Lys is a disease-causing mutation or a rare benign variant. The variant is found in EPILEPSY panel(s).
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