NM_000744.7:c.402G>A

Variant summary

Our verdict is Benign. The variant received -17 ACMG points: 0P and 17B. BP4_StrongBP6_Very_StrongBP7BS2

The NM_000744.7(CHRNA4):​c.402G>A​(p.Ala134Ala) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000516 in 1,613,130 control chromosomes in the GnomAD database, including 12 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★★).

Frequency

Genomes: 𝑓 0.00048 ( 2 hom., cov: 32)
Exomes 𝑓: 0.00052 ( 10 hom. )

Consequence

CHRNA4
NM_000744.7 synonymous

Scores

2

Clinical Significance

Benign/Likely benign criteria provided, multiple submitters, no conflicts B:5

Conservation

PhyloP100: -5.29

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 -17 ACMG points.

BP4
Computational evidence support a benign effect (BayesDel_noAF=-0.89).
BP6
Variant 20-63351009-C-T is Benign according to our data. Variant chr20-63351009-C-T is described in ClinVar as Benign/Likely_benign. ClinVar VariationId is 136756.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
BP7
Synonymous conserved (PhyloP=-5.28 with no splicing effect.
BS2
High AC in GnomAd4 at 73 AD gene.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
CHRNA4NM_000744.7 linkc.402G>A p.Ala134Ala synonymous_variant Exon 5 of 6 ENST00000370263.9 NP_000735.1 P43681-1B4DK78Q59FV0
CHRNA4NR_046317.2 linkn.611G>A non_coding_transcript_exon_variant Exon 5 of 6
CHRNA4NM_001256573.2 linkc.-127G>A 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.402G>A p.Ala134Ala synonymous_variant Exon 5 of 6 1 NM_000744.7 ENSP00000359285.4 P43681-1

Frequencies

GnomAD3 genomes
AF:
0.000481
AC:
73
AN:
151920
Hom.:
2
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.0000726
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00154
Gnomad SAS
AF:
0.0116
Gnomad FIN
AF:
0.000283
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.0000441
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.00113
AC:
283
AN:
249416
AF XY:
0.00147
show subpopulations
Gnomad AFR exome
AF:
0.0000621
Gnomad AMR exome
AF:
0.0000290
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00218
Gnomad FIN exome
AF:
0.000514
Gnomad NFE exome
AF:
0.0000445
Gnomad OTH exome
AF:
0.000820
GnomAD4 exome
AF:
0.000519
AC:
759
AN:
1461092
Hom.:
10
Cov.:
40
AF XY:
0.000726
AC XY:
528
AN XY:
726782
show subpopulations
African (AFR)
AF:
0.0000597
AC:
2
AN:
33476
American (AMR)
AF:
0.0000447
AC:
2
AN:
44710
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
East Asian (EAS)
AF:
0.000957
AC:
38
AN:
39698
South Asian (SAS)
AF:
0.00699
AC:
603
AN:
86250
European-Finnish (FIN)
AF:
0.000474
AC:
25
AN:
52712
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.0000297
AC:
33
AN:
1111962
Other (OTH)
AF:
0.000927
AC:
56
AN:
60380
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.478
Heterozygous variant carriers
0
63
126
189
252
315
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Exome Hom
Variant carriers
0
20
40
60
80
100
<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:
0.000480
AC:
73
AN:
152038
Hom.:
2
Cov.:
32
AF XY:
0.000673
AC XY:
50
AN XY:
74284
show subpopulations
African (AFR)
AF:
0.0000724
AC:
3
AN:
41448
American (AMR)
AF:
0.00
AC:
0
AN:
15270
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3466
East Asian (EAS)
AF:
0.00154
AC:
8
AN:
5178
South Asian (SAS)
AF:
0.0116
AC:
56
AN:
4808
European-Finnish (FIN)
AF:
0.000283
AC:
3
AN:
10590
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
294
European-Non Finnish (NFE)
AF:
0.0000441
AC:
3
AN:
67966
Other (OTH)
AF:
0.00
AC:
0
AN:
2108
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.482
Heterozygous variant carriers
0
4
8
12
16
20
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Genome Hom
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:
0.000128
Hom.:
0
Bravo
AF:
0.000117
Asia WGS
AF:
0.00433
AC:
16
AN:
3478
EpiCase
AF:
0.0000545
EpiControl
AF:
0.0000593

ClinVar

Significance: Benign/Likely benign
Submissions summary: Benign:5
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not specified Benign:2
Mar 19, 2015
Eurofins Ntd Llc (ga)
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Jul 09, 2013
GeneDx
Significance: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
Jan 30, 2025
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Inborn genetic diseases Benign:1
Jul 26, 2016
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. -

not provided Benign:1
Apr 16, 2018
Athena Diagnostics
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_noAF
Benign
-0.89
CADD
Benign
0.053
DANN
Benign
0.85
PhyloP100
-5.3
Mutation Taster
=99/1
polymorphism

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.020
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: rs201488442; hg19: chr20-61982361; API