20-63361131-A-G

Position:

chr20-63361131-A-G

Variant summary

Our verdict is Benign. Variant got -7 ACMG points: 0P and 7B. BP4_ModerateBP6BS2

The NM_000744.7(CHRNA4):c.35T>C(p.Leu12Pro) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000676 in 1,479,016 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 13/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

Frequency

Genomes: 𝑓 0.000020 ( 0 hom., cov: 31)

Exomes 𝑓: 0.0000053 ( 0 hom. )

Consequence

CHRNA4
NM_000744.7 missense

Scores

Clinical Significance

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

Conservation

PhyloP100: -0.345

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 links:

(HGNC:):

links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Benign. Variant got -7 ACMG points.

BP4

Computational evidence support a benign effect (MetaRNN=0.15282238).

BP6

Variant 20-63361131-A-G is Benign according to our data. Variant chr20-63361131-A-G is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 411848.We mark this variant Likely_benign, oryginal submissions are: {Likely_benign=1, Uncertain_significance=1}.

BS2

High AC in GnomAdExome4 at 7 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein
CHRNA4	NM_000744.7 linkuse as main transcript	c.35T>C	p.Leu12Pro	missense_variant	1/6	ENST00000370263.9	NP_000735.1
LOC100130587	NR_110634.1 linkuse as main transcript	n.183-687A>G		intron_variant, non_coding_transcript_variant
CHRNA4	NM_001256573.2 linkuse as main transcript	c.-471+46T>C		intron_variant			NP_001243502.1
CHRNA4	NR_046317.2 linkuse as main transcript	n.219T>C		non_coding_transcript_exon_variant	1/6

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
CHRNA4	ENST00000370263.9 linkuse as main transcript	c.35T>C	p.Leu12Pro	missense_variant	1/6	1	NM_000744.7	ENSP00000359285	P1	P43681-1
	ENST00000370257.1 linkuse as main transcript	n.183-687A>G		intron_variant, non_coding_transcript_variant		2

Frequencies

GnomAD3 genomes

AF:

0.0000198

AC:

AN:

151876

Hom.:

Cov.:

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:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000442

Gnomad OTH

AF:

0.00

GnomAD4 exome

AF:

0.00000527

AC:

AN:

1327140

Hom.:

Cov.:

AF XY:

0.00000459

AC XY:

AN XY:

653468

show subpopulations

Gnomad4 AFR exome

AF:

0.0000371

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00000570

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

AF:

0.0000198

AC:

AN:

151876

Hom.:

Cov.:

AF XY:

0.0000404

AC XY:

AN XY:

74178

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000442

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000712

Hom.:

Bravo

AF:

0.0000151

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:1Benign:1

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

not specified

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Jan 22, 2021

Variant summary: CHRNA4 c.35T>C (p.Leu12Pro) results in a non-conservative amino acid change in the encoded protein sequence. Four of five in-silico tools predict a benign effect of the variant on protein function. The variant allele was found at a frequency of 2e-05 in 150656 control chromosomes (gnomAD v3.1). The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. To our knowledge, no occurrence of c.35T>C in individuals affected with Epilepsy, Nocturnal Frontal Lobe, Type 1 and no experimental evidence demonstrating its impact on protein function have been reported. A ClinVar submitter (evaluation after 2014) cites the variant as uncertain significance. Based on the evidence outlined above, the variant was classified as uncertain significance. -

Autosomal dominant nocturnal frontal lobe epilepsy

Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jan 08, 2024

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.047

BayesDel_addAF

Benign

-0.025

BayesDel_noAF

Benign

-0.27

CADD

Benign

8.6

DANN

Benign

0.44

DEOGEN2

Benign

0.13

Eigen

Benign

-1.5

Eigen_PC

Benign

-1.6

FATHMM_MKL

Benign

0.018

LIST_S2

Benign

0.26

M_CAP

Pathogenic

0.86

MetaRNN

Benign

0.15

MetaSVM

Benign

-0.96

MutationAssessor

Benign

1.6

MutationTaster

Benign

1.0

PrimateAI

Pathogenic

0.80

PROVEAN

Benign

-0.61

REVEL

Uncertain

0.34

Sift

Benign

0.24

Sift4G

Benign

0.16

Polyphen

0.0

Vest4

0.20

MutPred

0.51

Gain of glycosylation at L12 (P = 0.0136);

MVP

0.45

MPC

0.64

ClinPred

0.050

GERP RS

-4.0

Varity_R

0.30

gMVP

0.75

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.010

Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over