rs773526895

Variant names:

Variant summary

Our verdict is Pathogenic. Variant got 10 ACMG points: 10P and 0B. PVS1_ModeratePP5_Very_Strong

The NM_000080.4(CHRNE):c.1353dupG(p.Asn452GlufsTer4) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000781 in 1,587,524 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Pathogenic (★★).

Frequency

Genomes: 𝑓 0.000059 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000080 ( 0 hom. )

Consequence

CHRNE
NM_000080.4 frameshift

Scores

Not classified

Clinical Significance

Pathogenic criteria provided, multiple submitters, no conflicts P:10O:1

Conservation

PhyloP100: -0.655

Variant links:

Genes affected

CHRNE (HGNC:1966): (cholinergic receptor nicotinic epsilon subunit) Acetylcholine receptors at mature mammalian neuromuscular junctions are pentameric protein complexes composed of four subunits in the ratio of two alpha subunits to one beta, one epsilon, and one delta subunit. The acetylcholine receptor changes subunit composition shortly after birth when the epsilon subunit replaces the gamma subunit seen in embryonic receptors. Mutations in the epsilon subunit are associated with congenital myasthenic syndrome. [provided by RefSeq, Sep 2009]

CHRNE links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 10 ACMG points.

PVS1

Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant is located in the 3'-most exon, not predicted to undergo nonsense mediated mRNA decay. Fraction of 0.087 CDS is truncated, and there are 2 pathogenic variants in the truncated region.

PP5

Variant 17-4898864-T-TC is Pathogenic according to our data. Variant chr17-4898864-T-TC is described in ClinVar as [Pathogenic]. Clinvar id is 243032.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CHRNE	NM_000080.4 link	c.1353dupG	p.Asn452GlufsTer4	frameshift_variant	Exon 12 of 12	ENST00000649488.2	NP_000071.1	Q04844
CHRNE	XM_017024115.2 link	c.1317dupG	p.Asn440GlufsTer4	frameshift_variant	Exon 13 of 13		XP_016879604.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	UniProt
CHRNE	ENST00000649488.2 link	c.1353dupG	p.Asn452GlufsTer4	frameshift_variant	Exon 12 of 12		NM_000080.4	ENSP00000497829.1	Q04844
CHRNE	ENST00000649830.1 link	c.529dupG	p.Glu177GlyfsTer56	frameshift_variant	Exon 11 of 11			ENSP00000496907.1	A0A3B3IRM1
CHRNE	ENST00000572438.1 link	n.1039dupG		non_coding_transcript_exon_variant	Exon 7 of 7	5
CHRNE	ENST00000652550.1 link	n.1079dupG		non_coding_transcript_exon_variant	Exon 4 of 4

Frequencies

GnomAD3 genomes

AF:

0.0000592

AC:

AN:

152048

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000242

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00202

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000147

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.000148

AC:

AN:

202640

Hom.:

AF XY:

0.000193

AC XY:

AN XY:

108914

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.0000712

Gnomad ASJ exome

AF:

0.00265

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000450

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000801

AC:

115

AN:

1435476

Hom.:

Cov.:

AF XY:

0.0000857

AC XY:

AN XY:

711552

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.0000510

Gnomad4 ASJ exome

AF:

0.00290

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000227

Gnomad4 OTH exome

AF:

0.000202

GnomAD4 genome

AF:

0.0000592

AC:

AN:

152048

Hom.:

Cov.:

AF XY:

0.0000539

AC XY:

AN XY:

74274

show subpopulations

Gnomad4 AFR

AF:

0.0000242

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00202

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000147

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.000374

Hom.:

Bravo

AF:

0.000113

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:10Other:1

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Congenital myasthenic syndrome 4A

Pathogenic:2

Mar 27, 2024

Baylor Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Nov 25, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change creates a premature translational stop signal (p.Asn452Glufs*4) in the CHRNE gene. While this is not anticipated to result in nonsense mediated decay, it is expected to disrupt the last 42 amino acid(s) of the CHRNE protein. This variant is present in population databases (rs773526895, gnomAD 0.3%). This premature translational stop signal has been observed in individuals with autosomal recessive congenital myasthenic syndrome (PMID: 8957026, 15951177, 19064877, 21175599, 28024842, 29054425). This variant is also known as 1293insG. ClinVar contains an entry for this variant (Variation ID: 243032). Algorithms developed to predict the effect of variants on gene product structure and function are not available or were not evaluated for this variant. Experimental studies have shown that this premature translational stop signal affects CHRNE function (PMID: 8957026). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. For these reasons, this variant has been classified as Pathogenic. -

Congenital myasthenic syndrome 4C;C4225369:Congenital myasthenic syndrome 4B;C4225413:Congenital myasthenic syndrome 4A

Pathogenic:2

Apr 26, 2024

Fulgent Genetics, Fulgent Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Mar 19, 2021

New York Genome Center

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Congenital myasthenic syndrome 4C

Pathogenic:2

Dec 09, 2008

OMIM

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: literature only

- -

Baylor Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

not provided

Pathogenic:2

Apr 30, 2022

Revvity Omics, Revvity

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Nov 07, 2022

GeneDx

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Reported previously using alternate nomenclature (c.1293insG) in multiple individuals with congenital myasthenia, and is noted to be a founder mutation in Northern Africa (Beeson et al., 2005; Richard et al., 2008; Mihaylova et al., 2010; Maselli et al., 2011); Published functional studies demostrate severely reduced cell surface expression and absent channel activity (Engel et al., 1996); Frameshift variant in the C-terminus predicted to result in protein truncation, as the last 42 amino acids are lost and replaced with three incorrect amino acids; This variant is associated with the following publications: (PMID: 20301347, 15951177, 8957026, 19064877, 20562457, 21175599, 29054425, 31589614, 10976646, 12536367) -

Congenital myasthenic syndrome

Pathogenic:1Other:1

Sep 16, 2020

Natera, Inc.

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

GeneReviews

Significance: not provided

Review Status: no classification provided

Collection Method: literature only

- -

Congenital myasthenic syndrome 4B

Pathogenic:1

May 22, 2022

3billion

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The variant is observed at an extremely low frequency in the gnomAD v2.1.1 dataset (total allele frequency: 0.013%). Frameshift: predicted to result in a loss or disruption of normal protein function through protein truncation. The predicted truncated protein may be shortened by less than 10%. Functional studies provide strong evidence of the variant having a damaging effect on the gene or gene product (PMID: 8957026). The variant has been reported at least twice as pathogenic without evidence for the classification (ClinVar ID: VCV000243032 / PMID: 8957026). Therefore, this variant is classified as pathogenic according to the recommendation of ACMG/AMP guideline. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.18

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