Genetic Variant NM_000749.5:c.347T>C (chr8-42730691-T-C) – ACMG Classification: Likely_pathogenic (6 pts)

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PM2PP3_Strong

The NM_000749.5(CHRNB3):c.347T>C(p.Val116Ala) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000424 in 1,438,910 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

Frequency

Genomes: not found (cov: 32)

Exomes 𝑓: 0.000042 ( 0 hom. )

Consequence

CHRNB3
NM_000749.5 missense

Scores

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 8.02

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:

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ACMG classification

Classification made for transcript

Verdict is Likely_pathogenic. Variant got 6 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

PP3

MetaRNN computational evidence supports a deleterious effect, 0.941

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CHRNB3	NM_000749.5 link	c.347T>C	p.Val116Ala	missense_variant	Exon 4 of 6	ENST00000289957.3	NP_000740.1	Q05901
CHRNB3	NM_001347717.2 link	c.125T>C	p.Val42Ala	missense_variant	Exon 5 of 7		NP_001334646.1
CHRNB3	XM_011544390.3 link	c.-41T>C		5_prime_UTR_variant	Exon 2 of 4		XP_011542692.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CHRNB3	ENST00000289957.3 link	c.347T>C	p.Val116Ala	missense_variant	Exon 4 of 6	1	NM_000749.5	ENSP00000289957.2		Q05901

Frequencies

GnomAD3 genomes

Cov.:

GnomAD3 exomes

AF:

0.00000822

AC:

AN:

243238

Hom.:

AF XY:

0.0000152

AC XY:

AN XY:

131536

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 SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000179

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000424

AC:

AN:

1438910

Hom.:

Cov.:

AF XY:

0.0000460

AC XY:

AN XY:

716714

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000557

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

Cov.:

Alfa

AF:

0.0000329

Hom.:

Bravo

AF:

0.0000264

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

Oct 01, 2024

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.347T>C (p.V116A) alteration is located in exon 4 (coding exon 4) of the CHRNB3 gene. This alteration results from a T to C substitution at nucleotide position 347, causing the valine (V) at amino acid position 116 to be replaced by an alanine (A). 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

Pathogenic

0.88

BayesDel_addAF

Pathogenic

0.37

BayesDel_noAF

Pathogenic

0.31

CADD

Uncertain

DANN

Pathogenic

1.0

DEOGEN2

Uncertain

0.63

Eigen

Pathogenic

0.86

Eigen_PC

Pathogenic

0.81

FATHMM_MKL

Pathogenic

0.99

LIST_S2

Uncertain

0.94

M_CAP

Uncertain

0.13

MetaRNN

Pathogenic

0.94

MetaSVM

Uncertain

0.55

MutationAssessor

Pathogenic

3.1

PrimateAI

Uncertain

0.79

PROVEAN

Uncertain

-3.7

REVEL

Pathogenic

0.93

Sift

Uncertain

0.0010

Sift4G

Uncertain

0.0020

Polyphen

1.0

Vest4

0.93

MVP

0.88

MPC

0.79

ClinPred

0.99

GERP RS

5.3

Varity_R

0.69

gMVP

0.56

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