8-42732433-A-C

Variant summary

Our verdict is Likely benign. Variant got -2 ACMG points: 2P and 4B. PM2BP4_Strong

The NM_000749.5(CHRNB3):c.1126A>C(p.Lys376Gln) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000274 in 1,461,844 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 16/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

Frequency

Genomes: not found (cov: 33)

Exomes 𝑓: 0.0000027 ( 0 hom. )

Consequence

CHRNB3
NM_000749.5 missense

Scores

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 0.990

Variant links:

Genes affected

CHRNB3 (HGNC:1963): (cholinergic receptor nicotinic beta 3 subunit) The nicotinic acetylcholine receptors (nAChRs) are members of a superfamily of ligand-gated ion channels that mediate fast signal transmission at synapses. The nAChRs are (hetero)pentamers composed of homologous subunits. The subunits that make up the muscle and neuronal forms of nAChRs are encoded by separate genes and have different primary structure. There are several subtypes of neuronal nAChRs that vary based on which homologous subunits are arranged around the central channel. They are classified as alpha-subunits if, like muscle alpha-1 (MIM 100690), they have a pair of adjacent cysteines as part of the presumed acetylcholine binding site. Subunits lacking these cysteine residues are classified as beta-subunits (Groot Kormelink and Luyten, 1997 [PubMed 9009220]). Elliott et al. (1996) [PubMed 8906617] stated that the proposed structure for each subunit is a conserved N-terminal extracellular domain followed by 3 conserved transmembrane domains, a variable cytoplasmic loop, a fourth conserved transmembrane domain, and a short C-terminal extracellular region.[supplied by OMIM, Apr 2010]

CHRNB3 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Likely_benign. Variant got -2 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

BP4

Computational evidence support a benign effect (MetaRNN=0.05689776).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE
CHRNB3	NM_000749.5 linkuse as main transcript	c.1126A>C	p.Lys376Gln	missense_variant	5/6	ENST00000289957.3
CHRNB3	NM_001347717.2 linkuse as main transcript	c.904A>C	p.Lys302Gln	missense_variant	6/7
CHRNB3	XM_011544390.3 linkuse as main transcript	c.739A>C	p.Lys247Gln	missense_variant	3/4

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
CHRNB3	ENST00000289957.3 linkuse as main transcript	c.1126A>C	p.Lys376Gln	missense_variant	5/6	1	NM_000749.5	P1

Frequencies

GnomAD3 genomes

Cov.:

GnomAD3 exomes

AF:

0.0000239

AC:

AN:

250986

Hom.:

AF XY:

0.0000221

AC XY:

AN XY:

135712

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.000327

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000274

AC:

AN:

1461844

Hom.:

Cov.:

AF XY:

0.00000275

AC XY:

AN XY:

727220

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.000101

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

Cov.:

Bravo

AF:

0.00000756

ExAC

AF:

0.00000824

AC:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

not specified

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Feb 26, 2024

The c.1126A>C (p.K376Q) alteration is located in exon 5 (coding exon 5) of the CHRNB3 gene. This alteration results from a A to C substitution at nucleotide position 1126, causing the lysine (K) at amino acid position 376 to be replaced by a glutamine (Q). 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

0.067

BayesDel_addAF

Benign

-0.42

BayesDel_noAF

Benign

-0.53

Cadd

Benign

Dann

Benign

0.67

DEOGEN2

Benign

0.22

Eigen

Benign

-0.73

Eigen_PC

Benign

-0.63

FATHMM_MKL

Benign

0.29

LIST_S2

Benign

0.57

M_CAP

Benign

0.016

MetaRNN

Benign

0.057

MetaSVM

Benign

-0.95

MutationAssessor

Benign

-0.53

MutationTaster

Benign

1.0

PrimateAI

Benign

0.25

PROVEAN

Benign

-0.49

REVEL

Benign

0.19

Sift

Benign

0.42

Sift4G

Benign

0.39

Polyphen

0.0030

Vest4

0.086

MutPred

0.43

Loss of methylation at K376 (P = 0.0164);

MVP

0.63

MPC

0.25

ClinPred

0.041

GERP RS

4.7

Varity_R

0.090

gMVP

0.26

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