2-151505476-A-G

Position:

chr2-151505476-A-G

Variant summary

Our verdict is Uncertain significance. Variant got 5 ACMG points: 5P and 0B. PVS1_ModeratePM2PP5

The NM_001164508.2(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

Genomes: 𝑓 0.000053 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000065 ( 0 hom. )

Consequence

NEB
NM_001164508.2 splice_donor, intron

Scores

Splicing: ADA: 0.9995

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:7U:1

Conservation

PhyloP100: 5.95

Variant links:

Genes affected

NEB (HGNC:7720): (nebulin) This gene encodes nebulin, a giant protein component of the cytoskeletal matrix that coexists with the thick and thin filaments within the sarcomeres of skeletal muscle. In most vertebrates, nebulin accounts for 3 to 4% of the total myofibrillar protein. The encoded protein contains approximately 30-amino acid long modules that can be classified into 7 types and other repeated modules. Protein isoform sizes vary from 600 to 800 kD due to alternative splicing that is tissue-, species-,and developmental stage-specific. Of the 183 exons in the nebulin gene, at least 43 are alternatively spliced, although exons 143 and 144 are not found in the same transcript. Of the several thousand transcript variants predicted for nebulin, the RefSeq Project has decided to create three representative RefSeq records. Mutations in this gene are associated with recessive nemaline myopathy. [provided by RefSeq, Sep 2009]

NEB links:

NEB (HGNC:):

NEB links:

RIF1 (HGNC:23207): (replication timing regulatory factor 1) This gene encodes a protein that shares homology with the yeast teleomere binding protein, Rap1 interacting factor 1. This protein localizes to aberrant telomeres may be involved in DNA repair. Alternate splicing results in multiple transcript variants. [provided by RefSeq, Apr 2010]

RIF1 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 5 ACMG points.

PVS1

Splicing +-2 bp (donor or acceptor) variant, product NOT destroyed by NMD, known LOF gene, truncates exone, which is 0.0035968411 fraction of the gene. No cryptic splice site detected. Exon removal is inframe change.

PM2

Very rare variant in population databases, with high coverage;

PP5

Variant 2-151505476-A-G is Pathogenic according to our data. Variant chr2-151505476-A-G is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 375408.We mark this variant Likely_pathogenic, oryginal submissions are: {Uncertain_significance=1, Likely_pathogenic=5}. Variant chr2-151505476-A-G is described in Lovd as [Likely_pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
NEB	NM_001164507.2 linkuse as main transcript	c.23742+2T>C		splice_donor_variant, intron_variant		ENST00000427231.7	NP_001157979.2
NEB	NM_001164508.2 linkuse as main transcript	c.23742+2T>C		splice_donor_variant, intron_variant		ENST00000397345.8	NP_001157980.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
NEB	ENST00000397345.8 linkuse as main transcript	c.23742+2T>C		splice_donor_variant, intron_variant		5	NM_001164508.2	ENSP00000380505.3		P20929-2
NEB	ENST00000427231.7 linkuse as main transcript	c.23742+2T>C		splice_donor_variant, intron_variant		5	NM_001164507.2	ENSP00000416578.2		P20929-3

Frequencies

GnomAD3 genomes

AF:

0.0000526

AC:

AN:

152170

Hom.:

Cov.:

show subpopulations

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:

0.000103

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000281

AC:

AN:

249022

Hom.:

AF XY:

0.0000370

AC XY:

AN XY:

135060

show subpopulations

Gnomad AFR exome

AF:

0.0000646

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:

0.0000532

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000650

AC:

AN:

1460742

Hom.:

Cov.:

AF XY:

0.0000688

AC XY:

AN XY:

726730

show subpopulations

Gnomad4 AFR exome

AF:

0.00

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:

0.0000819

Gnomad4 OTH exome

AF:

0.0000663

GnomAD4 genome

AF:

0.0000526

AC:

AN:

152170

Hom.:

Cov.:

AF XY:

0.0000538

AC XY:

AN XY:

74346

show subpopulations

Gnomad4 AFR

AF:

0.0000241

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.000103

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000772

Hom.:

Bravo

AF:

0.0000340

ExAC

AF:

0.0000165

AC:

EpiCase

AF:

0.0000545

EpiControl

AF:

0.000119

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:7Uncertain:1

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

Nemaline myopathy 2

Pathogenic:3

Likely pathogenic, no assertion criteria provided	clinical testing	Natera, Inc.	Sep 16, 2020	- -
Likely pathogenic, criteria provided, single submitter	clinical testing	Knight Diagnostic Laboratories, Oregon Health and Sciences University	Jun 27, 2016	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. -
Likely pathogenic, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Jan 31, 2024	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. -

not provided

Pathogenic:2

Likely pathogenic, criteria provided, single submitter	clinical testing	GeneDx	May 09, 2024	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) -
Likely pathogenic, criteria provided, single submitter	clinical testing	Revvity Omics, Revvity	Nov 24, 2019	- -

Arthrogryposis multiplex congenita 6

Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Baylor Genetics

Feb 26, 2024

- -

Nemaline myopathy 2;C5543431:Arthrogryposis multiplex congenita 6

Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Fulgent Genetics, Fulgent Genetics

Apr 22, 2024

- -

not specified

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Jul 25, 2019

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: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_addAF

Pathogenic

0.50

BayesDel_noAF

Pathogenic

0.27

CADD

Pathogenic

DANN

Uncertain

0.99

Eigen

Pathogenic

1.1

Eigen_PC

Pathogenic

0.92

FATHMM_MKL

Uncertain

0.97

GERP RS

5.5

Splicing

Name

Calibrated prediction

Score

Prediction

dbscSNV1_ADA

Pathogenic

1.0

dbscSNV1_RF

Pathogenic

0.84

SpliceAI score (max)

0.98

Details are displayed if max score is > 0.2

DS_DL_spliceai

0.98

Position offset: 2

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

Publications

LitVar

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over