rs121912243

Variant summary

Our verdict is Likely benign. The variant received -4 ACMG points: 1P and 5B. PP3BP6BS2

The NM_000744.7(CHRNA4):​c.442C>T​(p.Arg148Trp) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000242 in 1,613,700 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. R148Q) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000039 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000023 ( 0 hom. )

Consequence

CHRNA4
NM_000744.7 missense

Scores

3
13
2

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:3B:2O:1

Conservation

PhyloP100: 2.47

Publications

8 publications found
Variant links:
Genes affected
CHRNA4 (HGNC:1958): (cholinergic receptor nicotinic alpha 4 subunit) This gene encodes a nicotinic acetylcholine receptor, which belongs to a superfamily of ligand-gated ion channels that play a role in fast signal transmission at synapses. These pentameric receptors can bind acetylcholine, which causes an extensive change in conformation that leads to the opening of an ion-conducting channel across the plasma membrane. This protein is an integral membrane receptor subunit that can interact with either nAChR beta-2 or nAChR beta-4 to form a functional receptor. Mutations in this gene cause nocturnal frontal lobe epilepsy type 1. Polymorphisms in this gene that provide protection against nicotine addiction have been described. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Feb 2012]
CHRNA4 Gene-Disease associations (from GenCC):
  • autosomal dominant nocturnal frontal lobe epilepsy 1
    Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: G2P, Labcorp Genetics (formerly Invitae)
  • familial sleep-related hypermotor epilepsy
    Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
  • 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 -4 ACMG points.

PP3
MetaRNN computational evidence supports a deleterious effect, 0.768
BP6
Variant 20-63350969-G-A is Benign according to our data. Variant chr20-63350969-G-A is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 98324.
BS2
High AC in GnomAd4 at 6 AD gene.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000744.7. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
CHRNA4
NM_000744.7
MANE Select
c.442C>Tp.Arg148Trp
missense
Exon 5 of 6NP_000735.1P43681-1
CHRNA4
NM_001256573.2
c.-87C>T
5_prime_UTR
Exon 5 of 6NP_001243502.1Q4VAQ3
CHRNA4
NR_046317.2
n.651C>T
non_coding_transcript_exon
Exon 5 of 6

Ensembl Transcripts

Sel.
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
CHRNA4
ENST00000370263.9
TSL:1 MANE Select
c.442C>Tp.Arg148Trp
missense
Exon 5 of 6ENSP00000359285.4P43681-1
CHRNA4
ENST00000463705.5
TSL:1
n.1090C>T
non_coding_transcript_exon
Exon 4 of 5
CHRNA4
ENST00000467563.3
TSL:1
n.512C>T
non_coding_transcript_exon
Exon 5 of 6

Frequencies

GnomAD3 genomes
AF:
0.0000395
AC:
6
AN:
152084
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:
0.0000943
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.0000735
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000399
AC:
10
AN:
250556
AF XY:
0.0000368
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:
0.0000619
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000226
AC:
33
AN:
1461498
Hom.:
0
Cov.:
40
AF XY:
0.0000261
AC XY:
19
AN XY:
727016
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33480
American (AMR)
AF:
0.0000224
AC:
1
AN:
44718
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39700
South Asian (SAS)
AF:
0.0000464
AC:
4
AN:
86258
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53040
Middle Eastern (MID)
AF:
0.000693
AC:
4
AN:
5768
European-Non Finnish (NFE)
AF:
0.0000207
AC:
23
AN:
1112006
Other (OTH)
AF:
0.0000166
AC:
1
AN:
60392
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.480
Heterozygous variant carriers
0
3
5
8
10
13
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:
0.0000394
AC:
6
AN:
152202
Hom.:
0
Cov.:
32
AF XY:
0.0000538
AC XY:
4
AN XY:
74410
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41504
American (AMR)
AF:
0.00
AC:
0
AN:
15294
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5184
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4824
European-Finnish (FIN)
AF:
0.0000943
AC:
1
AN:
10604
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
294
European-Non Finnish (NFE)
AF:
0.0000735
AC:
5
AN:
68008
Other (OTH)
AF:
0.00
AC:
0
AN:
2108
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.508
Heterozygous variant carriers
0
1
1
2
2
3
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:
0.0000473
Hom.:
0
Bravo
AF:
0.00000756
ExAC
AF:
0.0000577
AC:
7
EpiCase
AF:
0.000109
EpiControl
AF:
0.0000593

ClinVar

ClinVar submissions
Significance:Conflicting classifications of pathogenicity
Revision:criteria provided, conflicting classifications
View on ClinVar
Pathogenic
VUS
Benign
Condition
-
-
1
Amyotrophic lateral sclerosis (1)
-
-
1
Autosomal dominant nocturnal frontal lobe epilepsy (1)
-
1
-
Inborn genetic diseases (1)
-
1
-
not provided (1)
-
1
-
not specified (1)
-
-
-
Tobacco use disorder (1)

Computational scores

Source: dbNSFP v4.9

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.13
BayesDel_addAF
Uncertain
0.065
T
BayesDel_noAF
Uncertain
0.060
CADD
Pathogenic
27
DANN
Pathogenic
1.0
DEOGEN2
Uncertain
0.65
D
Eigen
Uncertain
0.52
Eigen_PC
Uncertain
0.43
FATHMM_MKL
Uncertain
0.78
D
LIST_S2
Uncertain
0.94
D
M_CAP
Pathogenic
0.47
D
MetaRNN
Pathogenic
0.77
D
MetaSVM
Uncertain
0.43
D
MutationAssessor
Benign
1.9
L
PhyloP100
2.5
PrimateAI
Uncertain
0.56
T
PROVEAN
Uncertain
-3.1
D
REVEL
Uncertain
0.56
Sift
Uncertain
0.0080
D
Sift4G
Uncertain
0.013
D
Polyphen
1.0
D
Vest4
0.68
MVP
0.90
MPC
1.2
ClinPred
0.74
D
GERP RS
2.7
Varity_R
0.25
gMVP
0.73
Mutation Taster
=43/57
disease causing

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: rs121912243; hg19: chr20-61982321; COSMIC: COSV64719720; COSMIC: COSV64719720; API