rs545937015
Variant summary
Our verdict is Uncertain significance. The variant received 3 ACMG points: 3P and 0B. PVS1_ModeratePP5
The NM_001164507.2(NEB):c.23742+2T>C variant causes a splice donor, intron change. The variant allele was found at a frequency of 0.0000639 in 1,612,912 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 Conflicting classifications of pathogenicity (no stars).
Frequency
Consequence
NM_001164507.2 splice_donor, intron
Scores
Clinical Significance
Conservation
Publications
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ACMG classification
Our verdict: Uncertain_significance. The variant received 3 ACMG points.
Transcripts
RefSeq
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | MANE | Protein | UniProt |
|---|---|---|---|---|---|---|---|---|
| NEB | NM_001164507.2 | c.23742+2T>C | splice_donor_variant, intron_variant | Intron 165 of 181 | ENST00000427231.7 | NP_001157979.2 | ||
| NEB | NM_001164508.2 | c.23742+2T>C | splice_donor_variant, intron_variant | Intron 165 of 181 | ENST00000397345.8 | NP_001157980.2 |
Ensembl
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | TSL | MANE | Protein | Appris | UniProt |
|---|---|---|---|---|---|---|---|---|---|---|
| NEB | ENST00000397345.8 | c.23742+2T>C | splice_donor_variant, intron_variant | Intron 165 of 181 | 5 | NM_001164508.2 | ENSP00000380505.3 | |||
| NEB | ENST00000427231.7 | c.23742+2T>C | splice_donor_variant, intron_variant | Intron 165 of 181 | 5 | NM_001164507.2 | ENSP00000416578.2 |
Frequencies
GnomAD3 genomes AF: 0.0000526 AC: 8AN: 152170Hom.: 0 Cov.: 32 show subpopulations
GnomAD2 exomes AF: 0.0000281 AC: 7AN: 249022 AF XY: 0.0000370 show subpopulations
GnomAD4 exome AF: 0.0000650 AC: 95AN: 1460742Hom.: 0 Cov.: 30 AF XY: 0.0000688 AC XY: 50AN XY: 726730 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.0000526 AC: 8AN: 152170Hom.: 0 Cov.: 32 AF XY: 0.0000538 AC XY: 4AN XY: 74346 show subpopulations
Age Distribution
ClinVar
Submissions by phenotype
Nemaline myopathy 2 Pathogenic:3
The c.23847+2T>C splice variant in the NEB gene has not been previously reported in patients and this variant is absent (1000 Genomes; Exome Sequencing Project) or reported at low frequency in the population databases (ExAC = 0.01%; only 2 alleles). Splice-site, nonsense, and frameshift variants have been described in the NEB gene in multiple affected individuals (including nonsense and frameshift variants downstream of this variant) and thus, loss of function is a known mechanism of disease (GeneReviews: North and Ryan, 2015). Multiple in silico algorithms show high evolutionary conservation (CADD = 18.14; GERP=5.48), and in silico splicing algorithms predict this variant will cause altered splicing (Human Splice Finder=Broken WT Donor Site; SPIDEX=-3.228). Therefore, this collective evidence supports the classification of the c.23847+2T>C variant as a Likely pathogenic variant for Nemaline Myopathy 2. We have confirmed this finding in our laboratory using Sanger sequencing. -
This sequence change affects a donor splice site in intron 166 of the NEB 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 NEB are known to be pathogenic (PMID: 25205138). This variant is present in population databases (rs545937015, gnomAD 0.008%). This variant has not been reported in the literature in individuals affected with NEB-related conditions. ClinVar contains an entry for this variant (Variation ID: 375408). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. 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. -
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Nemaline myopathy Pathogenic:2
The c.23742+2T>C variant in NEB has not been previously reported in the literature in individuals with nemaline myopathy, but has been identified in 0.008% (98/1179056) of European (non-Finnish) chromosomes by the Genome Aggregation Database (gnomAD, http://gnomad.broadinstitute.org; dbSNP ID: rs545937015). Although this variant has been seen in the general population in a heterozygous state, its frequency is low enough to be consistent with a recessive carrier frequency. This variant has also been reported in ClinVar (Variation ID: 375408) and has been interpreted as likely pathogenic by Knight Diagnostic Laboratories (Oregon Health and Sciences University), Invitae, PerkinElmer Genomics, and Natera Inc., and as a variant of uncertain significance by the Laboratory for Molecular Medicine (Mass General Brigham Personalized Medicine). This variant is located in the 5' splice region. Computational tools predict a splicing impact, though this information is not predictive enough to determine pathogenicity. Loss of function of the NEB gene is an established disease mechanism in autosomal recessive nemaline myopathy. In summary, although additional studies are required to fully establish its clinical significance, this variant is likely pathogenic for autosomal recessive nemaline myopathy. ACMG/AMP Criteria applied: PVS1, PM2_supporting (Richards 2015). -
Variant summary: NEB c.23847+2T>C is located in a canonical splice-site and is predicted to affect mRNA splicing resulting in a significantly altered protein due to either exon skipping, shortening, or inclusion of intronic material. Variants that disrupt the consensus splice site are a relatively common cause of aberrant splicing and loss of NEB function. Several computational tools predict a significant impact on normal splicing: Two predict the variant abolishes a canonical 5' splicing donor site. However, these predictions have yet to be confirmed by functional studies. The variant allele was found at a frequency of 2.8e-05 in 249022 control chromosomes. To our knowledge, no occurrence of c.23847+2T>C in individuals affected with Nemaline Myopathy 2 and no experimental evidence demonstrating its impact on protein function have been reported. ClinVar contains an entry for this variant (Variation ID: 375408). Based on the evidence outlined above, the variant was classified as likely pathogenic. -
not provided Pathogenic:2
Reported as a single heterozygous variant in an individual undergoing preconception carrier screening (PMID: 29754767); Canonical splice site variant predicted to result in an in-frame loss of the adjacent exon in a gene for which loss of function is a known mechanism of disease; Not observed at significant frequency in large population cohorts (gnomAD); Deletions involving coding exons of this gene are a known mechanism of disease (HGMD); This variant is associated with the following publications: (PMID: 31589614, 29754767) -
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Nemaline myopathy 2;C5543431:Arthrogryposis multiplex congenita 6 Pathogenic:2
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Arthrogryposis multiplex congenita 6 Pathogenic:1
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not specified Uncertain:1
Variant classified as Uncertain Significance - Favor Pathogenic. The c.23847+2T>C variant in NEB has not been previously reported in individuals with myopathy but has been identified in 0.008% (10/128308) of European chromosomes by gnomAD (http://gnomad.broadinstitute.org). This variant has been reported in ClinVar (Variation ID: 375408). This variant occurs within the canonical splice site (+/- 1,2), but splicing predictors do not predict a significant change in splicing and the exons surrounding this variant are in-frame. In summary, while there is some suspicion for a pathogenic role, the clinical significance of this variant is uncertain. ACMG/AMP Criteria applied: PVS1_Moderate, PMS2 -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at