rs56142348

Variant summary

Our verdict is Benign. The variant received -10 ACMG points: 0P and 10B. BP4_StrongBP6BP7BS2

The NM_000744.7(CHRNA4):​c.1203G>C​(p.Leu401Leu) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00046 in 1,603,400 control chromosomes in the GnomAD database, including 7 homozygotes. In-silico tool predicts a benign 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. L401L) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.00060 ( 2 hom., cov: 32)
Exomes 𝑓: 0.00045 ( 5 hom. )

Consequence

CHRNA4
NM_000744.7 synonymous

Scores

2

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:1B:5

Conservation

PhyloP100: -1.11

Publications

3 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 -10 ACMG points.

BP4
Computational evidence support a benign effect (BayesDel_noAF=-0.86).
BP6
Variant 20-63350208-C-G is Benign according to our data. Variant chr20-63350208-C-G is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 136758.
BP7
Synonymous conserved (PhyloP=-1.11 with no splicing effect.
BS2
High AC in GnomAd4 at 92 AD gene.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
CHRNA4NM_000744.7 linkc.1203G>C p.Leu401Leu synonymous_variant Exon 5 of 6 ENST00000370263.9 NP_000735.1
CHRNA4NM_001256573.2 linkc.675G>C p.Leu225Leu synonymous_variant Exon 5 of 6 NP_001243502.1
CHRNA4NR_046317.2 linkn.1412G>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.1203G>C p.Leu401Leu synonymous_variant Exon 5 of 6 1 NM_000744.7 ENSP00000359285.4

Frequencies

GnomAD3 genomes
AF:
0.000605
AC:
92
AN:
152184
Hom.:
2
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.0000483
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.0000654
Gnomad ASJ
AF:
0.0213
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.000147
Gnomad OTH
AF:
0.00239
GnomAD2 exomes
AF:
0.000901
AC:
207
AN:
229768
AF XY:
0.000797
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.0185
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.000264
Gnomad OTH exome
AF:
0.00106
GnomAD4 exome
AF:
0.000445
AC:
646
AN:
1451216
Hom.:
5
Cov.:
98
AF XY:
0.000449
AC XY:
324
AN XY:
720922
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33358
American (AMR)
AF:
0.00
AC:
0
AN:
43490
Ashkenazi Jewish (ASJ)
AF:
0.0178
AC:
460
AN:
25804
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39332
South Asian (SAS)
AF:
0.00
AC:
0
AN:
85228
European-Finnish (FIN)
AF:
0.0000195
AC:
1
AN:
51258
Middle Eastern (MID)
AF:
0.000522
AC:
3
AN:
5752
European-Non Finnish (NFE)
AF:
0.0000958
AC:
106
AN:
1107038
Other (OTH)
AF:
0.00127
AC:
76
AN:
59956
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.487
Heterozygous variant carriers
0
45
90
136
181
226
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:
0.000605
AC:
92
AN:
152184
Hom.:
2
Cov.:
32
AF XY:
0.000552
AC XY:
41
AN XY:
74338
show subpopulations
African (AFR)
AF:
0.0000483
AC:
2
AN:
41450
American (AMR)
AF:
0.0000654
AC:
1
AN:
15290
Ashkenazi Jewish (ASJ)
AF:
0.0213
AC:
74
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5184
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4828
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10618
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.000147
AC:
10
AN:
68024
Other (OTH)
AF:
0.00239
AC:
5
AN:
2092
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.493
Heterozygous variant carriers
0
4
9
13
18
22
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:
0.00279
Hom.:
2
Bravo
AF:
0.000586

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Uncertain:1Benign:5
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

not specified Benign:2
Jul 03, 2017
Athena Diagnostics
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Sep 27, 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. -

not provided Uncertain:1
Feb 09, 2015
Eurofins Ntd Llc (ga)
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

CHRNA4-related disorder Benign:1
Apr 04, 2019
PreventionGenetics, part of Exact Sciences
Significance:Likely benign
Review Status:no assertion criteria provided
Collection Method:clinical testing

This variant is classified as likely benign based on ACMG/AMP sequence variant interpretation guidelines (Richards et al. 2015 PMID: 25741868, with internal and published modifications). -

Autosomal dominant nocturnal frontal lobe epilepsy Benign:1
Dec 28, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Inborn genetic diseases Benign:1
Nov 16, 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. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_noAF
Benign
-0.86
CADD
Benign
0.48
DANN
Benign
0.48
PhyloP100
-1.1
Mutation Taster
=100/0
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: rs56142348; hg19: chr20-61981560; COSMIC: COSV64720217; API