chr1-154571362-G-A

Variant summary

Our verdict is Likely benign. The variant received -6 ACMG points: 0P and 6B. BP4_ModerateBS2

The NM_000748.3(CHRNB2):​c.539G>A​(p.Arg180His) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000958 in 1,461,884 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R180L) has been classified as Uncertain significance.

Frequency

Genomes: not found (cov: 32)
Exomes 𝑓: 0.0000096 ( 0 hom. )

Consequence

CHRNB2
NM_000748.3 missense

Scores

4
15

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 3.24

Publications

4 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 -6 ACMG points.

BP4
Computational evidence support a benign effect (MetaRNN=0.17734078).
BS2
High AC in GnomAdExome4 at 14 AD gene.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
CHRNB2NM_000748.3 linkc.539G>A p.Arg180His missense_variant Exon 5 of 6 ENST00000368476.4 NP_000739.1 P17787Q5SXY3
CHRNB2XM_017000180.3 linkc.29G>A p.Arg10His missense_variant Exon 2 of 3 XP_016855669.1
CHRNB2XR_001736952.3 linkn.806G>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.539G>A p.Arg180His missense_variant Exon 5 of 6 1 NM_000748.3 ENSP00000357461.3 P17787
CHRNB2ENST00000637900.1 linkc.545G>A p.Arg182His missense_variant Exon 5 of 6 5 ENSP00000490474.1 A0A1B0GVD7
CHRNB2ENST00000636034.1 linkn.539G>A non_coding_transcript_exon_variant Exon 5 of 9 5 ENSP00000489703.1 A0A1B0GTH5

Frequencies

GnomAD3 genomes
Cov.:
32
GnomAD2 exomes
AF:
0.00000795
AC:
2
AN:
251418
AF XY:
0.00
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.0000992
Gnomad EAS exome
AF:
0.0000544
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000958
AC:
14
AN:
1461884
Hom.:
0
Cov.:
33
AF XY:
0.0000110
AC XY:
8
AN XY:
727244
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33480
American (AMR)
AF:
0.0000224
AC:
1
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.0000765
AC:
2
AN:
26136
East Asian (EAS)
AF:
0.000227
AC:
9
AN:
39700
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86258
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53412
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.00000180
AC:
2
AN:
1112010
Other (OTH)
AF:
0.00
AC:
0
AN:
60396
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.521
Heterozygous variant carriers
0
1
3
4
6
7
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
Cov.:
32
Alfa
AF:
0.00
Hom.:
0
Bravo
AF:
0.00000378
ExAC
AF:
0.00000824
AC:
1
Asia WGS
AF:
0.000289
AC:
1
AN:
3478

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:1
Revision: criteria provided, single submitter
LINK: link

Submissions by phenotype

Autosomal dominant nocturnal frontal lobe epilepsy Uncertain:1
Sep 21, 2020
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant is present in population databases (rs768297928, ExAC 0.001%). 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. Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be tolerated, but these predictions have not been confirmed by published functional studies and their clinical significance is uncertain. This variant has not been reported in the literature in individuals with CHRNB2-related disease. This sequence change replaces arginine with histidine at codon 180 of the CHRNB2 protein (p.Arg180His). The arginine residue is moderately conserved and there is a small physicochemical difference between arginine and histidine. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.093
BayesDel_addAF
Benign
-0.19
T
BayesDel_noAF
Benign
-0.34
CADD
Benign
23
DANN
Uncertain
0.99
DEOGEN2
Benign
0.30
T;.
Eigen
Benign
-0.28
Eigen_PC
Benign
-0.12
FATHMM_MKL
Uncertain
0.83
D
LIST_S2
Uncertain
0.92
D;D
M_CAP
Benign
0.025
D
MetaRNN
Benign
0.18
T;T
MetaSVM
Benign
-0.92
T
MutationAssessor
Benign
-0.11
N;.
PhyloP100
3.2
PrimateAI
Uncertain
0.66
T
PROVEAN
Benign
0.40
N;.
REVEL
Benign
0.16
Sift
Benign
0.18
T;.
Sift4G
Benign
0.18
T;.
Polyphen
0.057
B;.
Vest4
0.26
MutPred
0.64
Loss of sheet (P = 0.0817);.;
MVP
0.69
MPC
1.4
ClinPred
0.30
T
GERP RS
3.5
Varity_R
0.14
gMVP
0.80
Mutation Taster
=79/21
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: rs768297928; hg19: chr1-154543838; COSMIC: COSV63808975; COSMIC: COSV63808975; API