17-7445150-T-G

Position:

• chr17-7445150-T-G

Variant summary

Our verdict is Uncertain significance. Variant got 1 ACMG points: 2P and 1B. PM2 BP4

The NM_000747.3(CHRNB1):​c.23T>G​(p.Met8Arg) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. 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 Uncertain significance (★).

• Frequency: Genomes: not found (cov: 33)
• Consequence: CHRNB1 NM_000747.3 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 0.577

Genes affected

CHRNB1 (HGNC:1961): (cholinergic receptor nicotinic beta 1 subunit) The muscle acetylcholine receptor is composed of five subunits: two alpha subunits and one beta, one gamma, and one delta subunit. This gene encodes the beta subunit of the acetylcholine receptor. The acetylcholine receptor changes conformation upon acetylcholine binding leading to the opening of an ion-conducting channel across the plasma membrane. Mutations in this gene are associated with slow-channel congenital myasthenic syndrome. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Uncertain_significance. Variant got 1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.30854464).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
CHRNB1	NM_000747.3	c.23T>G	p.Met8Arg	missense_variant	1/11	ENST00000306071.7	NP_000738.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
CHRNB1	ENST00000306071.7	c.23T>G	p.Met8Arg	missense_variant	1/11	1	NM_000747.3	ENSP00000304290	P1
CHRNB1	ENST00000572857.5	c.23T>G	p.Met8Arg	missense_variant	1/6	4		ENSP00000461402
CHRNB1	ENST00000574054.1	n.43T>G		non_coding_transcript_exon_variant	1/2	2

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 33

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Congenital myasthenic syndrome 2A Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Aug 06, 2023

In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. Experimental studies and prediction algorithms are not available or were not evaluated, and the functional significance of this variant is currently unknown. This variant has not been reported in the literature in individuals affected with CHRNB1-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces methionine, which is neutral and non-polar, with arginine, which is basic and polar, at codon 8 of the CHRNB1 protein (p.Met8Arg). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.19
BayesDel_addAF	Uncertain	0.051	T
BayesDel_noAF	Benign	-0.16
CADD	Benign	20
DANN	Benign	0.94
DEOGEN2	Benign	0.25	T;.
Eigen	Benign	-0.65
Eigen_PC	Benign	-0.54
FATHMM_MKL	Benign	0.41	N
M_CAP	Benign	0.078	D
MetaRNN	Benign	0.31	T;T
MetaSVM	Benign	-0.82	T
MutationAssessor	Benign	0.0	N;.
MutationTaster	Benign	0.98	N;D
PrimateAI	Uncertain	0.65	T
PROVEAN	Benign	-2.3	N;.
REVEL	Uncertain	0.41
Sift	Benign	0.066	T;.
Sift4G	Uncertain	0.041	D;D
Polyphen		0.0050	B;.
Vest4		0.61
MutPred		0.68		Gain of methylation at M8 (P = 0.0084);Gain of methylation at M8 (P = 0.0084);
MVP		0.82
MPC		0.62
ClinPred		0.26	T
GERP RS		4.5
Varity_R		0.54
gMVP		0.73

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

No publications associated with this variant yet.

Other links and lift over

hg19: chr17-7348469;