1-154568045-A-G

Position:

• chr1-154568045-A-G

Variant summary

Our verdict is Pathogenic. Variant got 10 ACMG points: 10P and 0B. PVS1 PM2

The NM_000748.3(CHRNB2):​c.1A>G​(p.Met1?) variant causes a start lost change. The variant allele was found at a frequency of 0.00000208 in 1,441,624 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: 0.0000021 (0 hom.)
• Consequence: CHRNB2 NM_000748.3 start_lost
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 3.62

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]

CHRNB2 (HGNC:):

ACMG classification

Verdict is Pathogenic. Variant got 10 ACMG points.

• PVS1: Start lost variant, no new inframe start found.
• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
CHRNB2	NM_000748.3	c.1A>G	p.Met1?	start_lost	1/6	ENST00000368476.4	NP_000739.1
CHRNB2	XR_001736952.3	n.268A>G		non_coding_transcript_exon_variant	1/7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
CHRNB2	ENST00000368476.4	c.1A>G	p.Met1?	start_lost	1/6	1	NM_000748.3	ENSP00000357461.3
CHRNB2	ENST00000637900.1	c.1A>G	p.Met1?	start_lost	1/6	5		ENSP00000490474.1
CHRNB2	ENST00000636034.1	n.1A>G		non_coding_transcript_exon_variant	1/9	5		ENSP00000489703.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000208 AC: 3 AN: 1441624 Hom.: 0 Cov.: 31 AF XY: 0.00000279 AC XY: 2 AN XY: 715896

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.0000779

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.0000168

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

Labcorp Genetics (formerly Invitae), Labcorp

Nov 06, 2023

This sequence change affects the initiator methionine of the CHRNB2 mRNA. The next in-frame methionine is located at codon 61. This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with CHRNB2-related conditions. Experimental studies and prediction algorithms are not available or were not evaluated, and the functional significance of this variant is currently unknown. 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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.33	D
BayesDel_noAF	Pathogenic	0.24
CADD	Benign	23
DANN	Uncertain	0.99
DEOGEN2	Benign	0.24	T;.
Eigen	Benign	0.059
Eigen_PC	Benign	0.14
FATHMM_MKL	Benign	0.081	N
LIST_S2	Uncertain	0.90	D;D
M_CAP	Pathogenic	0.56	D
MetaRNN	Pathogenic	0.98	D;D
MetaSVM	Benign	-0.54	T
PROVEAN	Benign	-0.73	N;.
REVEL	Uncertain	0.50
Sift	Pathogenic	0.0	D;.
Sift4G	Pathogenic	0.0	D;.
Polyphen		0.32	B;.
Vest4		0.92
MutPred		0.99		Gain of methylation at R4 (P = 0.1119);Gain of methylation at R4 (P = 0.1119);
MVP		0.97
ClinPred		0.86	D
GERP RS		4.4
Varity_R		0.81
gMVP		0.71

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: chr1-154540521;