rs755303686

Variant names:

• chr17-4899385-C-G
• rs755303686
• NM_000080.4:c.1033-1G>C

Variant summary

Our verdict is Pathogenic. The variant received 16 ACMG points: 16P and 0B. PVS1 PP5_Very_Strong

The NM_000080.4(CHRNE):​c.1033-1G>C variant causes a splice acceptor, intron change. The variant allele was found at a frequency of 0.0000196 in 1,533,896 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Likely pathogenic (★★).

• Frequency:
  • Genomes: 𝑓 0.000013 (0 hom., cov: 33)
  • Exomes 𝑓: 0.000020 (0 hom.)
• Consequence: CHRNE NM_000080.4 splice_acceptor, intron
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:6
• Conservation: PhyloP100: 3.71
• Publications: 0 publications found

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]

C17orf107 (HGNC:37238): (chromosome 17 open reading frame 107)

ACMG classification

Our verdict: Pathogenic. The variant received 16 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, LoF is a know mechanism of disease, No cryptic splice site detected. Exon removal results in frameshift change.
• PP5: Variant 17-4899385-C-G is Pathogenic according to our data. Variant chr17-4899385-C-G is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 420092.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	c.1033-1G>C		splice_acceptor_variant, intron_variant	Intron 9 of 11	ENST00000649488.2	NP_000071.1
C17orf107	NM_001145536.2	c.-378C>G		upstream_gene_variant		ENST00000381365.4	NP_001139008.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CHRNE	ENST00000649488.2	c.1033-1G>C		splice_acceptor_variant, intron_variant	Intron 9 of 11		NM_000080.4	ENSP00000497829.1
C17orf107	ENST00000381365.4	c.-378C>G		upstream_gene_variant		2	NM_001145536.2	ENSP00000370770.3

Frequencies

GnomAD3 genomes AF: 0.0000132 AC: 2 AN: 152088 Hom.: 0 Cov.: 33

Gnomad AFR AF: 0.0000241

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: 0.0000147

Gnomad OTH AF: 0.00

GnomAD2 exomes AF: 0.00000754 AC: 1 AN: 132702 AF XY: 0.00

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000200

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000203 AC: 28 AN: 1381808 Hom.: 0 Cov.: 35 AF XY: 0.0000161 AC XY: 11 AN XY: 681872

African (AFR) AF: 0.00 AC: 0 AN: 31248

American (AMR) AF: 0.00 AC: 0 AN: 33746

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 24394

East Asian (EAS) AF: 0.00 AC: 0 AN: 35884

South Asian (SAS) AF: 0.00 AC: 0 AN: 78792

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 39298

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 4720

European-Non Finnish (NFE) AF: 0.0000260 AC: 28 AN: 1076358

Other (OTH) AF: 0.00 AC: 0 AN: 57368

GnomAD4 genome AF: 0.0000132 AC: 2 AN: 152088 Hom.: 0 Cov.: 33 AF XY: 0.0000135 AC XY: 1 AN XY: 74298

African (AFR) AF: 0.0000241 AC: 1 AN: 41448

American (AMR) AF: 0.00 AC: 0 AN: 15286

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3472

East Asian (EAS) AF: 0.00 AC: 0 AN: 5176

South Asian (SAS) AF: 0.00 AC: 0 AN: 4834

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10560

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 314

European-Non Finnish (NFE) AF: 0.0000147 AC: 1 AN: 67994

Other (OTH) AF: 0.00 AC: 0 AN: 2092

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.0000302

ExAC AF: 0.0000104 AC: 1

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:6

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Pathogenic:4

Dec 21, 2023

Revvity Omics, Revvity

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Apr 10, 2025

GeneDx

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Canonical splice site variant predicted to result in a null allele in a gene for which loss of function is a known mechanism of disease; Not observed at significant frequency in large population cohorts (gnomAD); This variant is associated with the following publications: (PMID: 14532324) -

Jun 30, 2022

Mayo Clinic Laboratories, Mayo Clinic

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

PM2, PVS1_strong -

May 15, 2017

Center for Pediatric Genomic Medicine, Children's Mercy Hospital and Clinics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Congenital myasthenic syndrome 4A Pathogenic:2

Feb 06, 2024

Baylor Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Feb 07, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change affects an acceptor splice site in intron 9 of the CHRNE gene. It is expected to disrupt RNA splicing. Variants that disrupt the donor or acceptor splice site typically lead to a loss of protein function (PMID: 16199547), and loss-of-function variants in CHRNE are known to be pathogenic (PMID: 22678886). The frequency data for this variant in the population databases is considered unreliable, as metrics indicate poor data quality at this position in the gnomAD database. Disruption of this splice site has been observed in individual(s) with clinical features of autosomal recessive congenital myasthenic syndrome (Invitae). In at least one individual the data is consistent with being in trans (on the opposite chromosome) from a pathogenic variant. ClinVar contains an entry for this variant (Variation ID: 420092). 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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Benign	-0.24
CADD	Uncertain	25
DANN	Benign	0.88
Eigen	Uncertain	0.48
Eigen_PC	Benign	0.21
FATHMM_MKL	Uncertain	0.90	D
PhyloP100		3.7
GERP RS		3.7
PromoterAI		0.10	Neutral
Mutation Taster		=1/99	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.96
SpliceAI score (max)		0.98		Details are displayed if max score is > 0.2
DS_AG_spliceai		0.31		Position offset: -13
DS_AL_spliceai		0.98		Position offset: -1

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Other links and lift over

dbSNP: rs755303686; hg19: chr17-4802680;