NM_000080.4:c.764C>G

Variant names:

• chr17-4901028-G-C
• NM_000080.4:c.764C>G

Variant summary

Our verdict is Pathogenic. Variant got 10 ACMG points: 10P and 0B. PM2 PM5 PP3_Strong PP5_Moderate

The NM_000080.4(CHRNE):​c.764C>G​(p.Ser255Trp) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,694 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 Likely pathogenic (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. S255L) has been classified as Pathogenic.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: CHRNE NM_000080.4 missense
• Clinical Significance: Likely pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 10.0

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

Verdict is Pathogenic. Variant got 10 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr17-4901028-G-A is described in Lovd as [Pathogenic].
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.951
• PP5: Variant 17-4901028-G-C is Pathogenic according to our data. Variant chr17-4901028-G-C is described in ClinVar as [Likely_pathogenic]. Clinvar id is 2880649.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CHRNE	NM_000080.4	c.764C>G	p.Ser255Trp	missense_variant	Exon 7 of 12	ENST00000649488.2	NP_000071.1
C17orf107	NM_001145536.2	c.*495G>C		3_prime_UTR_variant	Exon 3 of 3	ENST00000381365.4	NP_001139008.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CHRNE	ENST00000649488.2	c.764C>G	p.Ser255Trp	missense_variant	Exon 7 of 12		NM_000080.4	ENSP00000497829.1
C17orf107	ENST00000381365.4	c.*495G>C		3_prime_UTR_variant	Exon 3 of 3	2	NM_001145536.2	ENSP00000370770.3

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461694 Hom.: 0 Cov.: 34 AF XY: 0.00000138 AC XY: 1 AN XY: 727160

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.0000252

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

Congenital myasthenic syndrome 4A Pathogenic:1

Dec 05, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces serine, which is neutral and polar, with tryptophan, which is neutral and slightly polar, at codon 255 of the CHRNE protein (p.Ser255Trp). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with CHRNE-related conditions. 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 expected to disrupt CHRNE protein function. This variant disrupts the p.Ser255 amino acid residue in CHRNE. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 20562457, 28690392). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.93
BayesDel_addAF	Pathogenic	0.44	D
BayesDel_noAF	Pathogenic	0.39
CADD	Pathogenic	30
DANN	Uncertain	0.99
DEOGEN2	Pathogenic	0.92	D;D
Eigen	Pathogenic	1.0
Eigen_PC	Pathogenic	0.93
FATHMM_MKL	Pathogenic	0.97	D
LIST_S2	Pathogenic	0.98	.;D
M_CAP	Uncertain	0.22	D
MetaRNN	Pathogenic	0.95	D;D
MetaSVM	Pathogenic	0.98	D
MutationAssessor	Pathogenic	4.0	H;H
PrimateAI	Uncertain	0.73	T
PROVEAN	Pathogenic	-6.0	D;.
REVEL	Pathogenic	0.90
Sift	Pathogenic	0.0	D;.
Sift4G	Pathogenic	0.0010	D;.
Polyphen		1.0	D;D
Vest4		0.78
MutPred		0.75		Loss of glycosylation at S255 (P = 0.0087);Loss of glycosylation at S255 (P = 0.0087);
MVP		0.97
MPC		0.82
ClinPred		1.0	D
GERP RS		5.0
Varity_R		0.97
gMVP		0.97

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: chr17-4804323;