chr17-4900805-G-A

Position:

• chr17-4900805-G-A

Variant summary

Our verdict is Likely pathogenic. Variant got 9 ACMG points: 9P and 0B. PM1 PM5 PP3_Strong PP5

The NM_000080.4(CHRNE):​c.905C>T​(p.Pro302Leu) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000411 in 1,461,466 control chromosomes in the GnomAD database, including 1 homozygotes. In-silico tool predicts a pathogenic outcome for this variant. 12/21 in silico tools predict a damaging outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. P302R) has been classified as Likely pathogenic.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000041 (1 hom.)
• Consequence: CHRNE NM_000080.4 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1 U:1
• Conservation: PhyloP100: 7.89

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 Likely_pathogenic. Variant got 9 ACMG points.

• PM1: In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 7 uncertain in NM_000080.4
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr17-4900805-G-C is described in ClinVar as [Likely_pathogenic]. Clinvar id is 372325.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.981
• PP5: Variant 17-4900805-G-A is Pathogenic according to our data. Variant chr17-4900805-G-A is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 285424.We mark this variant Likely_pathogenic, oryginal submissions are: {Likely_pathogenic=1, Uncertain_significance=1}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
CHRNE	NM_000080.4	c.905C>T	p.Pro302Leu	missense_variant	8/12	ENST00000649488.2
C17orf107	NM_001145536.2	c.*272G>A		3_prime_UTR_variant	3/3	ENST00000381365.4

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
CHRNE	ENST00000649488.2	c.905C>T	p.Pro302Leu	missense_variant	8/12		NM_000080.4	P1
C17orf107	ENST00000381365.4	c.*272G>A		3_prime_UTR_variant	3/3	2	NM_001145536.2	A2

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD3 exomes AF: 0.00000404 AC: 1 AN: 247620 Hom.: 0 AF XY: 0.00 AC XY: 0 AN XY: 134468

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 SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000904

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000411 AC: 6 AN: 1461466 Hom.: 1 Cov.: 33 AF XY: 0.00000413 AC XY: 3 AN XY: 727024

Gnomad4 AFR exome AF: 0.0000299

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000450

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

ESP6500AA AF: 0.00 AC: 0

ESP6500EA AF: 0.000116 AC: 1

ExAC AF: 0.00000824 AC: 1

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:1 Uncertain:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Congenital myasthenic syndrome 4A Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Invitae

Dec 30, 2023

This sequence change replaces proline, which is neutral and non-polar, with leucine, which is neutral and non-polar, at codon 302 of the CHRNE protein (p.Pro302Leu). This variant is present in population databases (rs370019023, gnomAD 0.0009%). This variant has not been reported in the literature in individuals affected with CHRNE-related conditions. ClinVar contains an entry for this variant (Variation ID: 285424). 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 with a positive predictive value of 95%. This variant disrupts the p.Pro302 amino acid residue in CHRNE. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 22382357; Invitae). 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. -

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Eurofins Ntd Llc (ga)

Dec 30, 2015

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.93
BayesDel_addAF	Pathogenic	0.50	D
BayesDel_noAF	Pathogenic	0.48
CADD	Pathogenic	30
DANN	Pathogenic	1.0
DEOGEN2	Pathogenic	0.93	D;D
Eigen	Pathogenic	1.0
Eigen_PC	Pathogenic	0.94
FATHMM_MKL	Pathogenic	1.0	D
LIST_S2	Uncertain	0.95	.;D
M_CAP	Pathogenic	0.43	D
MetaRNN	Pathogenic	0.98	D;D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Pathogenic	3.8	H;H
MutationTaster	Benign	1.0	D;D
PrimateAI	Uncertain	0.74	T
PROVEAN	Pathogenic	-9.8	D;.
REVEL	Pathogenic	0.92
Sift	Uncertain	0.0010	D;.
Sift4G	Pathogenic	0.0	D;.
Polyphen		1.0	D;D
Vest4		0.96
MVP		0.97
MPC		0.70
ClinPred		1.0	D
GERP RS		5.0
Varity_R		0.98
gMVP		0.91

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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: rs370019023; hg19: chr17-4804100;