rs121909511
Variant summary
Our verdict is Pathogenic. Variant got 16 ACMG points: 16P and 0B. PM1PM2PP3_StrongPP5_Very_Strong
The NM_000080.4(CHRNE):c.865C>T(p.Leu289Phe) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★★).
Frequency
Consequence
NM_000080.4 missense
Scores
Clinical Significance
Conservation
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ACMG classification
Verdict is Pathogenic. Variant got 16 ACMG points.
Transcripts
RefSeq
Ensembl
Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | TSL | MANE | Protein | Appris | UniProt |
---|---|---|---|---|---|---|---|---|---|---|
CHRNE | ENST00000649488.2 | c.865C>T | p.Leu289Phe | missense_variant | Exon 8 of 12 | NM_000080.4 | ENSP00000497829.1 | |||
C17orf107 | ENST00000381365.4 | c.*312G>A | 3_prime_UTR_variant | Exon 3 of 3 | 2 | NM_001145536.2 | ENSP00000370770.3 |
Frequencies
GnomAD3 genomes Cov.: 33
GnomAD4 exome Cov.: 33
GnomAD4 genome Cov.: 33
ClinVar
Submissions by phenotype
Congenital myasthenic syndrome 4A Pathogenic:2
This sequence change replaces leucine, which is neutral and non-polar, with phenylalanine, which is neutral and non-polar, at codon 289 of the CHRNE protein (p.Leu289Phe). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individuals with autosomal dominant congenital myasthenic syndrome (PMID: 7538206, 8872460, 21822932, 27779167). It has also been observed to segregate with disease in related individuals. ClinVar contains an entry for this variant (Variation ID: 18344). 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 80%. Experimental studies have shown that this missense change affects CHRNE function (PMID: 8872460). For these reasons, this variant has been classified as Pathogenic. -
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not provided Pathogenic:1
DNA sequence analysis of the CHRNE gene demonstrated the likely pathogenic sequence change, c.865C>T in exon 8, that results in an amino acid change, p.Leu289Phe. The p.Leu289Phe change affects a highly conserved amino acid residue located in a domain of the CHRNE protein that is known to be functional. In-silico pathogenicity prediction tools (SIFT, PolyPhen2, Align GVGD, REVEL) provide contradictory results for the p.Leu289Phe substitution. This particular amino acid change (previously reported as p.Leu269Phe) has been described in patients with slow-channel congenital myasthenic syndrome (PMID: 8872460, 7538206, 27779167). Functional expression studies showed that the p.Leu289Phe mutation slowed the rate of acetylcholine receptor channel closure and increased the apparent affinity for acetylcholine. The mutation also caused pathologic channel openings even in the absence of acetylcholine, resulting in a leaky channel (PMID: 8872460). -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at