dbSNP rs75593857: CHRNA4:p.Leu349Leu (chr20-63350364-C-T) – ACMG Classification: Benign (-15 pts)

Variant summary

Our verdict is Benign. The variant received -15 ACMG points: 0P and 15B. BP4_ModerateBP6_Very_StrongBP7BS2

The NM_000744.7(CHRNA4):c.1047G>A(p.Leu349Leu) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000504 in 1,613,716 control chromosomes in the GnomAD database, including 2 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★★).

Frequency

Genomes: 𝑓 0.0019 ( 0 hom., cov: 32)

Exomes 𝑓: 0.00036 ( 2 hom. )

Consequence

CHRNA4
NM_000744.7 synonymous

Scores

Clinical Significance

Benign/Likely benign criteria provided, multiple submitters, no conflicts B:8

Conservation

PhyloP100: 0.203

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: G2P, Labcorp Genetics (formerly Invitae)
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

CHRNA4 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Benign. The variant received -15 ACMG points.

BP4

Computational evidence support a benign effect (BayesDel_noAF=-0.45).

BP6

Variant 20-63350364-C-T is Benign according to our data. Variant chr20-63350364-C-T is described in ClinVar as Benign/Likely_benign. ClinVar VariationId is 128743.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

BP7

Synonymous conserved (PhyloP=0.203 with no splicing effect.

BS2

High AC in GnomAd4 at 286 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

Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
CHRNA4	NM_000744.7	MANE Select	c.1047G>A	p.Leu349Leu	synonymous	Exon 5 of 6	NP_000735.1	P43681-1
CHRNA4	NM_001256573.2		c.519G>A	p.Leu173Leu	synonymous	Exon 5 of 6	NP_001243502.1	Q4VAQ3
CHRNA4	NR_046317.2		n.1256G>A		non_coding_transcript_exon	Exon 5 of 6

Ensembl Transcripts

Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
CHRNA4	ENST00000370263.9	TSL:1 MANE Select	c.1047G>A	p.Leu349Leu	synonymous	Exon 5 of 6	ENSP00000359285.4	P43681-1
CHRNA4	ENST00000463705.5	TSL:1	n.1695G>A		non_coding_transcript_exon	Exon 4 of 5
CHRNA4	ENST00000467563.3	TSL:1	n.1117G>A		non_coding_transcript_exon	Exon 5 of 6

Frequencies

GnomAD3 genomes

AF:

0.00188

AC:

286

AN:

152210

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00637

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00118

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00316

Gnomad NFE

AF:

0.0000441

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.000710

AC:

178

AN:

250572

AF XY:

0.000575

show subpopulations

Gnomad AFR exome

AF:

0.00760

Gnomad AMR exome

AF:

0.00130

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000796

Gnomad OTH exome

AF:

0.000164

GnomAD4 exome

AF:

0.000361

AC:

528

AN:

1461388

Hom.:

Cov.:

AF XY:

0.000333

AC XY:

242

AN XY:

726994

show subpopulations

African (AFR)

AF:

0.00738

AC:

247

AN:

33480

American (AMR)

AF:

0.00125

AC:

AN:

44720

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26136

East Asian (EAS)

AF:

0.00

AC:

AN:

39700

South Asian (SAS)

AF:

0.0000116

AC:

AN:

86258

European-Finnish (FIN)

AF:

0.00

AC:

AN:

52934

Middle Eastern (MID)

AF:

0.00139

AC:

AN:

5768

European-Non Finnish (NFE)

AF:

0.000147

AC:

163

AN:

1112006

Other (OTH)

AF:

0.000878

AC:

AN:

60386

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.484

Heterozygous variant carriers

118

158

197

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Exome Hom

Variant carriers

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:

0.00188

AC:

286

AN:

152328

Hom.:

Cov.:

AF XY:

0.00191

AC XY:

142

AN XY:

74490

show subpopulations

African (AFR)

AF:

0.00635

AC:

264

AN:

41568

American (AMR)

AF:

0.00118

AC:

AN:

15310

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3472

East Asian (EAS)

AF:

0.00

AC:

AN:

5176

South Asian (SAS)

AF:

0.00

AC:

AN:

4828

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10630

Middle Eastern (MID)

AF:

0.00340

AC:

AN:

294

European-Non Finnish (NFE)

AF:

0.0000441

AC:

AN:

68028

Other (OTH)

AF:

0.00

AC:

AN:

2112

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.492

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Genome Het

Variant carriers

<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:

0.00205

Hom.:

Bravo

AF:

0.00221

Asia WGS

AF:

0.000866

AC:

AN:

3478

EpiCase

AF:

0.0000545

EpiControl

AF:

0.000178

ClinVar

ClinVar submissions

Significance:Benign/Likely benign

Revision:criteria provided, multiple submitters, no conflicts

View on ClinVar

Pathogenic

VUS

Benign

Condition

not specified (4)

not provided (2)

Autosomal dominant nocturnal frontal lobe epilepsy (1)

Inborn genetic diseases (1)

Computational scores

Source: dbNSFP v4.9

Name

Calibrated prediction

Score

Prediction

BayesDel_noAF

Benign

-0.45

CADD

Benign

9.0

(source)

DANN

Benign

0.77

PhyloP100

0.20

Mutation Taster

=100/0

polymorphism

(source)

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

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Variant Effect in Transcripts

RefSeq Transcripts

Ensembl Transcripts

Frequencies

Age Distribution

Age Distribution

ClinVar

Computational scores

Splicing

Publications

Other links and lift over