Genetic Variant CHRNB4:p.Met300Val (chr15-78629407-T-C) – ACMG Classification: Uncertain_significance (2 pts)

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 2P and 0B. PM2

The NM_000750.5(CHRNB4):c.898A>G(p.Met300Val) variant causes a missense change. The variant allele was found at a frequency of 0.00000547 in 1,461,852 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★).

Frequency

Genomes: not found (cov: 32)

Exomes 𝑓: 0.0000055 ( 0 hom. )

Consequence

CHRNB4
NM_000750.5 missense

Scores

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 5.02

Variant links:

Genes affected

CHRNB4 (HGNC:1964): (cholinergic receptor nicotinic beta 4 subunit) This gene is found within a conserved gene cluster and encodes one of the beta subunits of the nicotinic acetylcholine receptor (nAChRs) superfamily which form ligand-gated ion channels with a central pore that forms a cation channel. Neuronal nAChRs are pentameric structures that can be either homomeric or heteromeric, with heteromeric structures containing both alpha and beta subunits. Each subunit contains an extracellular amino terminus and four transmembrane domains. Nicotine is one of the agonists that binds to the receptor. Variants in this gene have been associated with nicotine dependence and lung cancer. Alternative splicing results in multiple transcript variants encoding different isoforms. [provided by RefSeq, Sep 2017]

CHRNB4 links:

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ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 2 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CHRNB4	NM_000750.5 link	c.898A>G	p.Met300Val	missense_variant	Exon 5 of 6	ENST00000261751.8	NP_000741.1	P30926-1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	UniProt
CHRNB4	ENST00000261751.8 link	c.898A>G	p.Met300Val	missense_variant	Exon 5 of 6	1	NM_000750.5	ENSP00000261751.3	P30926-1
CHRNB4	ENST00000412074.6 link	c.359+1669A>G		intron_variant	Intron 4 of 4	1		ENSP00000416386.2	P30926-2
CHRNB4	ENST00000559849.5 link	n.*954A>G		non_coding_transcript_exon_variant	Exon 12 of 12	1		ENSP00000457404.1	H3BU02
CHRNB4	ENST00000559849.5 link	n.*954A>G		3_prime_UTR_variant	Exon 12 of 12	1		ENSP00000457404.1	H3BU02

Frequencies

GnomAD3 genomes

Cov.:

GnomAD3 exomes

AF:

0.00000795

AC:

AN:

251426

Hom.:

AF XY:

0.00000736

AC XY:

AN XY:

135884

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.0000544

Gnomad SAS exome

AF:

0.0000327

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000547

AC:

AN:

1461852

Hom.:

Cov.:

AF XY:

0.00000550

AC XY:

AN XY:

727232

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.0000252

Gnomad4 SAS exome

AF:

0.0000116

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00000450

Gnomad4 OTH exome

AF:

0.0000166

GnomAD4 genome

Cov.:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

not specified

Uncertain:1

Jul 14, 2023

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.898A>G (p.M300V) alteration is located in exon 5 (coding exon 5) of the CHRNB4 gene. This alteration results from a A to G substitution at nucleotide position 898, causing the methionine (M) at amino acid position 300 to be replaced by a valine (V). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.18

BayesDel_addAF

Uncertain

0.020

BayesDel_noAF

Uncertain

-0.040

CADD

Benign

DANN

Uncertain

0.99

DEOGEN2

Uncertain

0.46

Eigen

Uncertain

0.29

Eigen_PC

Uncertain

0.33

FATHMM_MKL

Uncertain

0.93

LIST_S2

Uncertain

0.93

M_CAP

Uncertain

0.13

MetaRNN

Uncertain

0.69

MetaSVM

Uncertain

0.065

MutationAssessor

Uncertain

2.4

PrimateAI

Uncertain

0.77

PROVEAN

Uncertain

-2.5

REVEL

Pathogenic

0.67

Sift

Benign

0.068

Sift4G

Benign

0.077

Polyphen

0.51

Vest4

0.70

MutPred

0.66

Gain of catalytic residue at M300 (P = 0.0031);

MVP

0.71

MPC

0.46

ClinPred

0.58

GERP RS

4.3

Varity_R

0.29

gMVP

0.78

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

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