NM_000747.3:c.39G>C

Variant names:

• chr17-7445166-G-C
• rs770359368
• NM_000747.3:c.39G>C

Variant summary

Our verdict is Likely benign. Variant got -6 ACMG points: 0P and 6B. BP4_Strong BP6 BP7

The NM_000747.3(CHRNB1):​c.39G>C​(p.Leu13Leu) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000367 in 1,609,032 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

• Frequency:
  • Genomes: 𝑓 0.000013 (0 hom., cov: 33)
  • Exomes 𝑓: 0.000039 (0 hom.)
• Consequence: CHRNB1 NM_000747.3 synonymous
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:1 B:1
• Conservation: PhyloP100: -1.26

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]

ENSG00000272884 (HGNC:):

ACMG classification

Verdict is Likely_benign. Variant got -6 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.81).
• BP6: Variant 17-7445166-G-C is Benign according to our data. Variant chr17-7445166-G-C is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 725792.We mark this variant Likely_benign, oryginal submissions are: {Likely_benign=1, Uncertain_significance=1}.
• BP7: Synonymous conserved (PhyloP=-1.26 with no splicing effect.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CHRNB1	NM_000747.3	c.39G>C	p.Leu13Leu	synonymous_variant	Exon 1 of 11	ENST00000306071.7	NP_000738.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CHRNB1	ENST00000306071.7	c.39G>C	p.Leu13Leu	synonymous_variant	Exon 1 of 11	1	NM_000747.3	ENSP00000304290.2
ENSG00000272884	ENST00000575331.1	n.4753G>C		non_coding_transcript_exon_variant	Exon 3 of 3	1
CHRNB1	ENST00000572857.5	c.39G>C	p.Leu13Leu	synonymous_variant	Exon 1 of 6	4		ENSP00000461402.1
CHRNB1	ENST00000574054.1	n.59G>C		non_coding_transcript_exon_variant	Exon 1 of 2	2

Frequencies

GnomAD3 genomes AF: 0.0000131 AC: 2 AN: 152228 Hom.: 0 Cov.: 33

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000294

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.0000342 AC: 8 AN: 233668 Hom.: 0 AF XY: 0.0000310 AC XY: 4 AN XY: 129042

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.000118

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.0000516

Gnomad NFE exome AF: 0.0000291

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000391 AC: 57 AN: 1456804 Hom.: 0 Cov.: 31 AF XY: 0.0000455 AC XY: 33 AN XY: 724664

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.000112

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.0000199

Gnomad4 NFE exome AF: 0.0000459

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome AF: 0.0000131 AC: 2 AN: 152228 Hom.: 0 Cov.: 33 AF XY: 0.0000269 AC XY: 2 AN XY: 74370

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000294

Gnomad4 OTH AF: 0.00

Alfa AF: 0.0000283 Hom.: 0

Bravo AF: 0.0000227

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:1 Benign:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Congenital myasthenic syndrome 4C Uncertain:1

Jan 13, 2018

Illumina Laboratory Services, Illumina

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -

Congenital myasthenic syndrome 2A Benign:1

Dec 19, 2023

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.81
CADD	Benign	4.6
DANN	Benign	0.58
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.6

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: rs770359368; hg19: chr17-7348485;