rs199916140

Variant summary

Our verdict is Benign. The variant received -14 ACMG points: 0P and 14B. BP4_ModerateBP6_Very_StrongBS2

The NM_000744.7(CHRNA4):​c.1269G>C​(p.Lys423Asn) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000261 in 1,571,394 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 16/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★★).

Frequency

Genomes: 𝑓 0.00013 ( 0 hom., cov: 33)
Exomes 𝑓: 0.000015 ( 0 hom. )

Consequence

CHRNA4
NM_000744.7 missense

Scores

1
18

Clinical Significance

Likely benign criteria provided, multiple submitters, no conflicts B:2

Conservation

PhyloP100: -0.0430

Publications

1 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: Benign. The variant received -14 ACMG points.

BP4
Computational evidence support a benign effect (MetaRNN=0.08827996).
BP6
Variant 20-63350142-C-G is Benign according to our data. Variant chr20-63350142-C-G is described in ClinVar as Likely_benign. ClinVar VariationId is 420616.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
BS2
High AC in GnomAd4 at 20 AD gene.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
CHRNA4NM_000744.7 linkc.1269G>C p.Lys423Asn missense_variant Exon 5 of 6 ENST00000370263.9 NP_000735.1 P43681-1B4DK78Q59FV0
CHRNA4NM_001256573.2 linkc.741G>C p.Lys247Asn missense_variant Exon 5 of 6 NP_001243502.1 P43681Q4VAQ3B4DK78Q59FV0
CHRNA4NR_046317.2 linkn.1478G>C non_coding_transcript_exon_variant Exon 5 of 6

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
CHRNA4ENST00000370263.9 linkc.1269G>C p.Lys423Asn missense_variant Exon 5 of 6 1 NM_000744.7 ENSP00000359285.4 P43681-1

Frequencies

GnomAD3 genomes
AF:
0.000131
AC:
20
AN:
152160
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.000483
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:
0.00
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000305
AC:
6
AN:
196642
AF XY:
0.0000189
show subpopulations
Gnomad AFR exome
AF:
0.000411
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:
0.0000118
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000148
AC:
21
AN:
1419234
Hom.:
0
Cov.:
83
AF XY:
0.00000857
AC XY:
6
AN XY:
700410
show subpopulations
African (AFR)
AF:
0.000366
AC:
12
AN:
32756
American (AMR)
AF:
0.000125
AC:
5
AN:
40036
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
24724
East Asian (EAS)
AF:
0.00
AC:
0
AN:
38158
South Asian (SAS)
AF:
0.00
AC:
0
AN:
81380
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
49920
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5640
European-Non Finnish (NFE)
AF:
0.00000276
AC:
3
AN:
1088090
Other (OTH)
AF:
0.0000171
AC:
1
AN:
58530
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.480
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
AF:
0.000131
AC:
20
AN:
152160
Hom.:
0
Cov.:
33
AF XY:
0.0000538
AC XY:
4
AN XY:
74350
show subpopulations
African (AFR)
AF:
0.000483
AC:
20
AN:
41434
American (AMR)
AF:
0.00
AC:
0
AN:
15284
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3466
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5182
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4834
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:
0.00
AC:
0
AN:
68030
Other (OTH)
AF:
0.00
AC:
0
AN:
2092
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.463
Heterozygous variant carriers
0
1
2
4
5
6
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:
0.0000858
Hom.:
0
Bravo
AF:
0.000200
ExAC
AF:
0.0000417
AC:
5

ClinVar

Significance: Likely benign
Submissions summary: Benign:2
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not specified Benign:1
May 08, 2017
GeneDx
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant is considered likely benign or benign based on one or more of the following criteria: it is a conservative change, it occurs at a poorly conserved position in the protein, it is predicted to be benign by multiple in silico algorithms, and/or has population frequency not consistent with disease. -

Autosomal dominant nocturnal frontal lobe epilepsy Benign:1
Dec 02, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.15
BayesDel_addAF
Benign
-0.38
T
BayesDel_noAF
Benign
-0.46
CADD
Benign
9.0
DANN
Benign
0.97
DEOGEN2
Benign
0.33
T;.
Eigen
Benign
-0.92
Eigen_PC
Benign
-0.99
FATHMM_MKL
Benign
0.25
N
LIST_S2
Benign
0.66
T;T
M_CAP
Uncertain
0.12
D
MetaRNN
Benign
0.088
T;T
MetaSVM
Benign
-0.89
T
MutationAssessor
Benign
2.0
M;.
PhyloP100
-0.043
PrimateAI
Benign
0.31
T
PROVEAN
Benign
-0.12
N;.
REVEL
Benign
0.12
Sift
Benign
0.15
T;.
Sift4G
Benign
0.45
T;T
Polyphen
0.17
B;.
Vest4
0.22
MutPred
0.38
Loss of methylation at K423 (P = 8e-04);.;
MVP
0.87
MPC
0.64
ClinPred
0.029
T
GERP RS
-0.040
Varity_R
0.12
gMVP
0.22
Mutation Taster
=88/12
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: rs199916140; hg19: chr20-61981494; API