rs121912244

Variant summary

Our verdict is Likely benign. The variant received -1 ACMG points: 4P and 5B. PP3_StrongBP6BS2

The NM_000744.7(CHRNA4):​c.461C>T​(p.Pro154Leu) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000961 in 1,613,674 control chromosomes in the GnomAD database, including 1 homozygotes. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Synonymous variant affecting the same amino acid position (i.e. P154P) has been classified as Benign.

Frequency

Genomes: 𝑓 0.000059 ( 0 hom., cov: 32)
Exomes 𝑓: 0.00010 ( 1 hom. )

Consequence

CHRNA4
NM_000744.7 missense

Scores

14
4
1

Clinical Significance

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

Conservation

PhyloP100: 9.78

Publications

4 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: Labcorp Genetics (formerly Invitae), G2P
  • 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 -1 ACMG points.

PP3
MetaRNN computational evidence supports a deleterious effect, 0.961
BP6
Variant 20-63350950-G-A is Benign according to our data. Variant chr20-63350950-G-A is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 98325.
BS2
High AC in GnomAd4 at 9 AD gene.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
CHRNA4NM_000744.7 linkc.461C>T p.Pro154Leu missense_variant Exon 5 of 6 ENST00000370263.9 NP_000735.1 P43681-1B4DK78Q59FV0
CHRNA4NM_001256573.2 linkc.-68C>T 5_prime_UTR_premature_start_codon_gain_variant Exon 5 of 6 NP_001243502.1 P43681Q4VAQ3B4DK78Q59FV0
CHRNA4NR_046317.2 linkn.670C>T non_coding_transcript_exon_variant Exon 5 of 6
CHRNA4NM_001256573.2 linkc.-68C>T 5_prime_UTR_variant Exon 5 of 6 NP_001243502.1 P43681Q4VAQ3B4DK78Q59FV0

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
CHRNA4ENST00000370263.9 linkc.461C>T p.Pro154Leu missense_variant Exon 5 of 6 1 NM_000744.7 ENSP00000359285.4 P43681-1

Frequencies

GnomAD3 genomes
AF:
0.0000592
AC:
9
AN:
152074
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.0000242
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.000131
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.000207
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.0000735
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000518
AC:
13
AN:
250824
AF XY:
0.0000442
show subpopulations
Gnomad AFR exome
AF:
0.000123
Gnomad AMR exome
AF:
0.0000868
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000530
Gnomad OTH exome
AF:
0.000163
GnomAD4 exome
AF:
0.0000999
AC:
146
AN:
1461600
Hom.:
1
Cov.:
40
AF XY:
0.000105
AC XY:
76
AN XY:
727072
show subpopulations
African (AFR)
AF:
0.0000896
AC:
3
AN:
33480
American (AMR)
AF:
0.0000894
AC:
4
AN:
44720
Ashkenazi Jewish (ASJ)
AF:
0.0000383
AC:
1
AN:
26136
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39700
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86258
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53144
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.000121
AC:
134
AN:
1112002
Other (OTH)
AF:
0.0000662
AC:
4
AN:
60392
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.485
Heterozygous variant carriers
0
12
23
35
46
58
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
10
20
30
40
50
<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:
0.0000592
AC:
9
AN:
152074
Hom.:
0
Cov.:
32
AF XY:
0.0000942
AC XY:
7
AN XY:
74284
show subpopulations
African (AFR)
AF:
0.0000242
AC:
1
AN:
41394
American (AMR)
AF:
0.000131
AC:
2
AN:
15270
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3468
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5190
South Asian (SAS)
AF:
0.000207
AC:
1
AN:
4828
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10610
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000735
AC:
5
AN:
68002
Other (OTH)
AF:
0.00
AC:
0
AN:
2084
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.508
Heterozygous variant carriers
0
1
2
3
4
5
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:
0.000137
Hom.:
0
Bravo
AF:
0.0000567
ESP6500AA
AF:
0.000227
AC:
1
ESP6500EA
AF:
0.00
AC:
0
ExAC
AF:
0.0000412
AC:
5
EpiCase
AF:
0.00
EpiControl
AF:
0.000178

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Uncertain:2Benign:1Other:1
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

not provided Uncertain:2
Nov 17, 2017
Athena Diagnostics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Oct 29, 2021
GeneDx
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; Has not been previously published as pathogenic or benign to our knowledge; This variant is associated with the following publications: (PMID: 21683344) -

Autosomal dominant nocturnal frontal lobe epilepsy Benign:1
Jul 15, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Tobacco use disorder Other:1
-
Psychiatry Genetics Yale University
Significance:not provided
Review Status:no classification provided
Collection Method:literature only

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.90
BayesDel_addAF
Pathogenic
0.32
D
BayesDel_noAF
Pathogenic
0.42
CADD
Pathogenic
32
DANN
Uncertain
1.0
DEOGEN2
Pathogenic
0.83
D;.
Eigen
Pathogenic
1.0
Eigen_PC
Pathogenic
0.89
FATHMM_MKL
Uncertain
0.96
D
LIST_S2
Uncertain
0.94
D;D
M_CAP
Pathogenic
0.59
D
MetaRNN
Pathogenic
0.96
D;D
MetaSVM
Pathogenic
0.93
D
MutationAssessor
Pathogenic
4.1
H;.
PhyloP100
9.8
PrimateAI
Uncertain
0.71
T
PROVEAN
Pathogenic
-9.3
D;.
REVEL
Pathogenic
0.87
Sift
Pathogenic
0.0
D;.
Sift4G
Pathogenic
0.0
D;D
Polyphen
1.0
D;.
Vest4
0.93
MVP
0.94
MPC
1.2
ClinPred
1.0
D
GERP RS
4.9
Varity_R
0.84
gMVP
0.88
Mutation Taster
=16/84
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: rs121912244; hg19: chr20-61982302; COSMIC: COSV106517875; COSMIC: COSV106517875; API