1-154568057-T-G

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_000748.3(CHRNB2):c.13T>G(p.Cys5Gly) 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. 16/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. C5S) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 32)
• Consequence: CHRNB2 NM_000748.3 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 0.145

Genes affected

CHRNB2 (HGNC:1962): (cholinergic receptor nicotinic beta 2 subunit) Neuronal acetylcholine receptors are homo- or heteropentameric complexes composed of homologous alpha and beta subunits. They belong to a superfamily of ligand-gated ion channels which allow the flow of sodium and potassium across the plasma membrane in response to ligands such as acetylcholine and nicotine. This gene encodes one of several beta subunits. Mutations in this gene are associated with autosomal dominant nocturnal frontal lobe epilepsy. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Uncertain_significance. Variant got 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.1250337).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
CHRNB2	NM_000748.3	c.13T>G	p.Cys5Gly	missense_variant	1/6	ENST00000368476.4
CHRNB2	XR_001736952.3	n.280T>G		non_coding_transcript_exon_variant	1/7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
CHRNB2	ENST00000368476.4	c.13T>G	p.Cys5Gly	missense_variant	1/6	1	NM_000748.3	P4
CHRNB2	ENST00000637900.1	c.13T>G	p.Cys5Gly	missense_variant	1/6	5		A1
CHRNB2	ENST00000636034.1	c.13T>G	p.Cys5Gly	missense_variant, NMD_transcript_variant	1/9	5

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Autosomal dominant nocturnal frontal lobe epilepsy Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Dec 03, 2020

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. Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is not expected to disrupt CHRNB2 protein function. This variant has not been reported in the literature in individuals with CHRNB2-related conditions. This variant is not present in population databases (ExAC no frequency). This sequence change replaces cysteine with glycine at codon 5 of the CHRNB2 protein (p.Cys5Gly). The cysteine residue is weakly conserved and there is a large physicochemical difference between cysteine and glycine. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.049
BayesDel_addAF	Benign	-0.065	T
BayesDel_noAF	Benign	-0.33
Cadd	Benign	17
Dann	Benign	0.86
DEOGEN2	Benign	0.24	T;.
Eigen	Benign	-1.0
Eigen_PC	Benign	-0.97
FATHMM_MKL	Benign	0.0042	N
LIST_S2	Benign	0.41	T;T
M_CAP	Benign	0.018	T
MetaRNN	Benign	0.13	T;T
MetaSVM	Benign	-1.1	T
MutationAssessor	Benign	0.34	N;.
MutationTaster	Benign	1.0	N
PrimateAI	Benign	0.43	T
PROVEAN	Benign	-0.93	N;.
REVEL	Benign	0.19
Sift	Benign	0.051	T;.
Sift4G	Benign	0.38	T;.
Polyphen		0.0	B;.
Vest4		0.24
MutPred		0.67		Gain of relative solvent accessibility (P = 0.005);Gain of relative solvent accessibility (P = 0.005);
MVP		0.85
MPC		1.3
ClinPred		0.041	T
GERP RS		0.63
Varity_R		0.13
gMVP		0.51

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

Other links and lift over

dbSNP: rs1261047629; hg19: chr1-154540533;