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

Genomes: 𝑓 0.000013 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000018 ( 0 hom. )

Consequence

CHRNB2
NM_000748.3 missense

Scores

9
9

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:3B:1

Conservation

PhyloP100: 5.00

Publications

0 publications found
Variant links:
Genes affected
CHRNB2 (HGNC:1962): (cholinergic receptor nicotinic beta 2 subunit) Neuronal acetylcholine receptors are homo- or heteropentameric complexes composed of homologous alpha and beta subunits. They belong to a superfamily of ligand-gated ion channels which allow the flow of sodium and potassium across the plasma membrane in response to ligands such as acetylcholine and nicotine. This gene encodes one of several beta subunits. Mutations in this gene are associated with autosomal dominant nocturnal frontal lobe epilepsy. [provided by RefSeq, Jul 2008]
CHRNB2 Gene-Disease associations (from GenCC):
  • familial sleep-related hypermotor epilepsy
    Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
  • autosomal dominant nocturnal frontal lobe epilepsy 3
    Inheritance: AD Classification: STRONG Submitted by: G2P, Labcorp Genetics (formerly Invitae)
  • autosomal dominant nocturnal frontal lobe epilepsy
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_benign. The variant received -5 ACMG points.

BP6
Variant 1-154571463-G-A is Benign according to our data. Variant chr1-154571463-G-A is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 205069.
BS2
High AC in GnomAdExome4 at 27 AD gene.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
CHRNB2NM_000748.3 linkc.640G>A p.Glu214Lys missense_variant Exon 5 of 6 ENST00000368476.4 NP_000739.1
CHRNB2XM_017000180.3 linkc.130G>A p.Glu44Lys missense_variant Exon 2 of 3 XP_016855669.1
CHRNB2XR_001736952.3 linkn.907G>A non_coding_transcript_exon_variant Exon 5 of 7

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
CHRNB2ENST00000368476.4 linkc.640G>A p.Glu214Lys missense_variant Exon 5 of 6 1 NM_000748.3 ENSP00000357461.3
CHRNB2ENST00000637900.1 linkc.646G>A p.Glu216Lys missense_variant Exon 5 of 6 5 ENSP00000490474.1
CHRNB2ENST00000636034.1 linkn.640G>A non_coding_transcript_exon_variant Exon 5 of 9 5 ENSP00000489703.1

Frequencies

GnomAD3 genomes
AF:
0.0000131
AC:
2
AN:
152158
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.0000294
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000159
AC:
4
AN:
251304
AF XY:
0.0000147
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000264
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000185
AC:
27
AN:
1461810
Hom.:
0
Cov.:
33
AF XY:
0.0000179
AC XY:
13
AN XY:
727198
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33480
American (AMR)
AF:
0.00
AC:
0
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39700
South Asian (SAS)
AF:
0.0000116
AC:
1
AN:
86256
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53340
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.0000234
AC:
26
AN:
1112010
Other (OTH)
AF:
0.00
AC:
0
AN:
60396
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.479
Heterozygous variant carriers
0
2
4
6
8
10
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
GnomAD4 genome
AF:
0.0000131
AC:
2
AN:
152158
Hom.:
0
Cov.:
32
AF XY:
0.0000135
AC XY:
1
AN XY:
74322
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41428
American (AMR)
AF:
0.00
AC:
0
AN:
15286
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5192
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4834
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10612
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000294
AC:
2
AN:
68014
Other (OTH)
AF:
0.00
AC:
0
AN:
2092
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.500
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
Alfa
AF:
0.0000494
Hom.:
0
Bravo
AF:
0.00000378
ExAC
AF:
0.0000247
AC:
3
EpiCase
AF:
0.00
EpiControl
AF:
0.0000593

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Uncertain:3Benign:1
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

Autosomal dominant nocturnal frontal lobe epilepsy Uncertain:1
Oct 23, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

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
Oct 31, 2018
Fulgent Genetics, Fulgent Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

not provided Uncertain:1
Sep 10, 2013
GeneDx
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

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
Sep 24, 2024
Ambry Genetics
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

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: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.27
BayesDel_addAF
Benign
-0.087
T
BayesDel_noAF
Benign
-0.27
CADD
Pathogenic
26
DANN
Uncertain
1.0
DEOGEN2
Benign
0.40
T;.
Eigen
Uncertain
0.49
Eigen_PC
Uncertain
0.44
FATHMM_MKL
Uncertain
0.84
D
LIST_S2
Uncertain
0.92
D;D
M_CAP
Benign
0.056
D
MetaRNN
Uncertain
0.44
T;T
MetaSVM
Uncertain
-0.15
T
MutationAssessor
Benign
2.0
M;.
PhyloP100
5.0
PrimateAI
Uncertain
0.74
T
PROVEAN
Benign
-1.5
N;.
REVEL
Uncertain
0.47
Sift
Benign
0.11
T;.
Sift4G
Benign
0.44
T;.
Vest4
0.56
ClinPred
0.82
D
GERP RS
4.1
Varity_R
0.31
gMVP
0.86
Mutation Taster
=59/41
polymorphism

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

Publications

Other links and lift over

dbSNP: rs780175030; hg19: chr1-154543939; API