rs77345643

Variant summary

Our verdict is Benign. The variant received -7 ACMG points: 0P and 7B. BP4_ModerateBP6BS2

The NM_000744.7(CHRNA4):​c.1667C>T​(p.Pro556Leu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000149 in 1,612,330 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 Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. P556R) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 34)
Exomes 𝑓: 0.000015 ( 0 hom. )

Consequence

CHRNA4
NM_000744.7 missense

Scores

1
17

Clinical Significance

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

Conservation

PhyloP100: -1.17

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 -7 ACMG points.

BP4
Computational evidence support a benign effect (MetaRNN=0.078847975).
BP6
Variant 20-63349744-G-A is Benign according to our data. Variant chr20-63349744-G-A is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 422587.
BS2
High AC in GnomAdExome4 at 22 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

Selected
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
CHRNA4
NM_000744.7
MANE Select
c.1667C>Tp.Pro556Leu
missense
Exon 5 of 6NP_000735.1
CHRNA4
NM_001256573.2
c.1139C>Tp.Pro380Leu
missense
Exon 5 of 6NP_001243502.1
CHRNA4
NR_046317.2
n.1876C>T
non_coding_transcript_exon
Exon 5 of 6

Ensembl Transcripts

Selected
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
CHRNA4
ENST00000370263.9
TSL:1 MANE Select
c.1667C>Tp.Pro556Leu
missense
Exon 5 of 6ENSP00000359285.4
CHRNA4
ENST00000463705.5
TSL:1
n.2315C>T
non_coding_transcript_exon
Exon 4 of 5
CHRNA4
ENST00000467563.3
TSL:1
n.1737C>T
non_coding_transcript_exon
Exon 5 of 6

Frequencies

GnomAD3 genomes
AF:
0.0000131
AC:
2
AN:
152246
Hom.:
0
Cov.:
34
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:
0.000207
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00316
Gnomad NFE
AF:
0.00
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000121
AC:
3
AN:
247934
AF XY:
0.0000222
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:
0.0000180
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000151
AC:
22
AN:
1459966
Hom.:
0
Cov.:
34
AF XY:
0.0000220
AC XY:
16
AN XY:
726258
show subpopulations
African (AFR)
AF:
0.0000299
AC:
1
AN:
33466
American (AMR)
AF:
0.00
AC:
0
AN:
44680
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26090
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39678
South Asian (SAS)
AF:
0.0000232
AC:
2
AN:
86214
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
52196
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.0000135
AC:
15
AN:
1111526
Other (OTH)
AF:
0.0000663
AC:
4
AN:
60348
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.473
Heterozygous variant carriers
0
2
4
6
8
10
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:
0.0000131
AC:
2
AN:
152364
Hom.:
0
Cov.:
34
AF XY:
0.0000134
AC XY:
1
AN XY:
74508
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41588
American (AMR)
AF:
0.00
AC:
0
AN:
15306
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5186
South Asian (SAS)
AF:
0.000207
AC:
1
AN:
4832
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10628
Middle Eastern (MID)
AF:
0.00340
AC:
1
AN:
294
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
68034
Other (OTH)
AF:
0.00
AC:
0
AN:
2112
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.500
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
Alfa
AF:
0.0000434
Hom.:
0
ExAC
AF:
0.00000827
AC:
1

ClinVar

ClinVar submissions as Germline

Significance:Conflicting classifications of pathogenicity
Revision:criteria provided, conflicting classifications
View on ClinVar
Pathogenic
VUS
Benign
Condition
-
-
1
Autosomal dominant nocturnal frontal lobe epilepsy (1)
-
1
-
not provided (1)

Computational scores

Source: dbNSFP v4.9

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.073
BayesDel_addAF
Benign
-0.17
T
BayesDel_noAF
Benign
-0.39
CADD
Benign
0.23
DANN
Benign
0.74
DEOGEN2
Benign
0.28
T
Eigen
Benign
-1.5
Eigen_PC
Benign
-1.5
FATHMM_MKL
Benign
0.015
N
LIST_S2
Benign
0.15
T
M_CAP
Uncertain
0.16
D
MetaRNN
Benign
0.079
T
MetaSVM
Benign
-0.75
T
MutationAssessor
Benign
0.14
N
PhyloP100
-1.2
PrimateAI
Benign
0.26
T
PROVEAN
Benign
-0.36
N
REVEL
Benign
0.17
Sift
Benign
0.29
T
Sift4G
Benign
0.29
T
Polyphen
0.059
B
Vest4
0.13
MutPred
0.49
Loss of glycosylation at P556 (P = 0.0065)
MVP
0.61
MPC
0.46
ClinPred
0.027
T
GERP RS
-0.59
Varity_R
0.024
gMVP
0.24
Mutation Taster
=99/1
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: rs77345643; hg19: chr20-61981096; COSMIC: COSV108213365; COSMIC: COSV108213365; API