rs200449517

Positions:

chr2-151519656-A-G

Variant summary

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

The NM_001164507.2(NEB):c.22590+2T>C variant causes a splice donor change. The variant allele was found at a frequency of 0.000306 in 1,595,418 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 0.000092 ( 0 hom., cov: 32)

Exomes 𝑓: 0.00033 ( 0 hom. )

Consequence

NEB
NM_001164507.2 splice_donor

Scores

Splicing: ADA: 0.9960

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:8U:2

Conservation

PhyloP100: 6.75

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:

RIF1 (HGNC:):

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 0.0043005706 fraction of the gene. Cryptic splice site detected, with MaxEntScore 5.9, offset of -5, new splice context is: caaGTgagg. Cryptic site results in frameshift change. If cryptic site found is not functional and variant results in exon loss, it results in inframe change.

PM2

Very rare variant in population databases, with high coverage;

PP5

Variant 2-151519656-A-G is Pathogenic according to our data. Variant chr2-151519656-A-G is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 451052.We mark this variant Likely_pathogenic, oryginal submissions are: {Likely_pathogenic=7, Uncertain_significance=2}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
NEB	NM_001164507.2 linkuse as main transcript	c.22590+2T>C		splice_donor_variant		ENST00000427231.7	NP_001157979.2
NEB	NM_001164508.2 linkuse as main transcript	c.22590+2T>C		splice_donor_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.22590+2T>C		splice_donor_variant		5	NM_001164508.2	ENSP00000380505	P5	P20929-2
NEB	ENST00000427231.7 linkuse as main transcript	c.22590+2T>C		splice_donor_variant		5	NM_001164507.2	ENSP00000416578	A2	P20929-3

Frequencies

GnomAD3 genomes

AF:

0.0000920

AC:

AN:

152226

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:

0.000191

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000926

AC:

AN:

248252

Hom.:

AF XY:

0.0000742

AC XY:

AN XY:

134682

show subpopulations

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:

0.000196

Gnomad OTH exome

AF:

0.000166

GnomAD4 exome

AF:

0.000328

AC:

474

AN:

1443192

Hom.:

Cov.:

AF XY:

0.000310

AC XY:

223

AN XY:

719150

show subpopulations

Gnomad4 AFR exome

AF:

0.0000606

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:

0.000416

Gnomad4 OTH exome

AF:

0.000268

GnomAD4 genome

AF:

0.0000920

AC:

AN:

152226

Hom.:

Cov.:

AF XY:

0.0000403

AC XY:

AN XY:

74368

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:

0.000191

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.000203

Hom.:

Bravo

AF:

0.0000945

TwinsUK

AF:

0.000270

AC:

ALSPAC

AF:

0.000778

AC:

ESP6500AA

AF:

0.00

AC:

ESP6500EA

AF:

0.000122

AC:

ExAC

AF:

0.000116

AC:

EpiCase

AF:

0.000164

EpiControl

AF:

0.000297

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:8Uncertain:2

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

Nemaline myopathy 2

Pathogenic:4Uncertain:1

Likely pathogenic, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Jan 08, 2024	This sequence change affects a donor splice site in intron 155 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 (rs200449517, gnomAD 0.02%). 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: 451052). 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. -
Uncertain significance, criteria provided, single submitter	clinical testing	Illumina Laboratory Services, Illumina	Oct 30, 2018	The NEB c.17487+2T>C variant, which corresponds to c.22695+2T>C in the transcript NM_001271208.1, occurs in a canonical splice site (donor) and is therefore predicted to disrupt or distort the normal gene product. A literature search was performed for the gene and cDNA change. No publications were found through this search. The c.17487+2T>C variant is reported at a frequency of 0.000211 in the European (non-Finnish) population of the Exome Aggregation Consortium. Based on the potential impact of splice variants and the lack of clarifying evidence, the c.17487+2T>C variant is classified as of uncertain significance but suspicious for pathogenicity for nemaline myopathy. This variant was observed by ICSL as part of a predisposition screen in an ostensibly healthy population. -
Likely pathogenic, criteria provided, single submitter	clinical testing	Counsyl	Apr 05, 2017	- -
Likely pathogenic, no assertion criteria provided	clinical testing	Natera, Inc.	Sep 16, 2020	- -
Likely pathogenic, criteria provided, single submitter	clinical testing	Victorian Clinical Genetics Services, Murdoch Childrens Research Institute	Jun 24, 2022	Based on the classification scheme VCGS_Germline_v1.3.4, this variant is classified as likely pathogenic. Following criteria are met: 0102 - Loss of function is a known mechanism of disease in this gene and is associated with arthrogryposis multiplex congenita 6 (MIM#619334) and nemaline myopathy 2 (MIM#256030). (I) 0106 - This gene is associated with autosomal recessive disease. (I) 0115 - Variants in this gene are known to have variable expressivity (OMIM). (I) 0211 - Canonical splice site variant without proven consequence on splicing (no functional evidence available). (SP) 0251 - This variant is heterozygous. (I) 0304 - Variant is present in gnomAD (v2) <0.01 for a recessive condition (28 heterozygotes, 0 homozygotes). (SP) 0505 - Abnormal splicing is predicted by in silico tools and affected nucleotide is highly conserved. (SP) 0705 - No comparable canonical splice variants have previous evidence for pathogenicity. (I) 0802 - This variant has moderate previous evidence of pathogenicity in unrelated individuals. This variant has been reported once as a VUS, but multiple times as likely pathogenic but with limited clinical information. One individual had progressive muscle weakness and foot drop with a variant of uncertain significance in trans (ClinVar, personal communication). It has also been observed in a cohort with retinopathy (PMID: 28132693). (SP) 0905 - No published segregation evidence has been identified for this variant. (I) 1007 - No published functional evidence has been identified for this variant. (I) 1208 - Inheritance information for this variant is not currently available in this individual. (I) Legend: (SP) - Supporting pathogenic, (I) - Information, (SB) - Supporting benign -

not provided

Pathogenic:3

Likely pathogenic, criteria provided, single submitter	clinical testing	Revvity Omics, Revvity	Oct 02, 2020	- -
Likely pathogenic, criteria provided, single submitter	clinical testing	GeneDx	Feb 22, 2024	Canonical splice site variant expected to result in aberrant splicing, although in the absence of functional evidence the actual effect of this sequence change is unknown.; Deletions involving coding exons in this gene are frequently reported as pathogenic, regardless of frame prediction (HGMD); Has not been previously published as pathogenic or benign to our knowledge -
Likely pathogenic, criteria provided, single submitter	clinical testing	CeGaT Center for Human Genetics Tuebingen	Sep 01, 2017	- -

Nemaline myopathy

Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Jan 11, 2024

Variant summary: NEB c.22695+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. Several computational tools predict a significant impact on normal splicing: Three predict the variant abolishes a 5' splicing donor site, and one predicts the variant has no significant impact on splicing. However, these predictions have yet to be confirmed by functional studies. The variant allele was found at a frequency of 9.3e-05 in 248252 control chromosomes. This frequency is not significantly higher than estimated for a pathogenic variant in NEB causing Nemaline Myopathy 2 (9.3e-05 vs 0.0035), allowing no conclusion about variant significance. c.22695+2T>C has been reported in the literature in an individual affected with simplex Retinitis Pigmentosa without any familial history of Nemaline Myopathy and who did not have a reported second pathogenic variant (Arno_2017). This report does not provide unequivocal conclusions about association of the variant with Nemaline Myopathy 2. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. The following publication has been ascertained in the context of this evaluation (PMID: 28132693). ClinVar contains an entry for this variant (Variation ID: 451052). Based on the evidence outlined above, the variant was classified as likely pathogenic. -

Arthrogryposis multiplex congenita 6

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Baylor Genetics

Aug 09, 2023

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_addAF

Pathogenic

0.41

BayesDel_noAF

Pathogenic

0.38

CADD

Pathogenic

DANN

Uncertain

0.99

Eigen

Pathogenic

1.2

Eigen_PC

Pathogenic

1.0

FATHMM_MKL

Pathogenic

0.99

MutationTaster

Benign

1.0

D;D;D;D

GERP RS

6.2

Splicing

Name

Calibrated prediction

Score

Prediction

dbscSNV1_ADA

Pathogenic

1.0

dbscSNV1_RF

Pathogenic

0.72

SpliceAI score (max)

0.97

Details are displayed if max score is > 0.2

DS_DL_spliceai

0.97

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