chr2-151729615-C-T

Variant names:

• chr2-151729615-C-T
• rs1553702617
• NM_001164507.2:c.78G>A

Variant summary

Our verdict is Uncertain significance. The variant received 4 ACMG points: 4P and 0B. PM2 PP3_Moderate

The NM_001164507.2(NEB):​c.78G>A​(p.Glu26Glu) variant causes a splice region, synonymous change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: NEB NM_001164507.2 splice_region, synonymous
• Scores: Splicing: ADA: 0.9997
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 3.89
• Publications: 0 publications found

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 Gene-Disease associations (from GenCC):

• nemaline myopathy 2

  Inheritance: AR, AD Classification: DEFINITIVE, STRONG, LIMITED Submitted by: ClinGen, Labcorp Genetics (formerly Invitae), Myriad Women’s Health, G2P, Ambry Genetics
• childhood-onset nemaline myopathy

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• intermediate nemaline myopathy

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• typical nemaline myopathy

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• lethal multiple pterygium syndrome

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
• severe congenital nemaline myopathy

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Uncertain_significance. The variant received 4 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: Splicing predictors support a deleterious effect. Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF, max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
NEB	NM_001164507.2	c.78G>A	p.Glu26Glu	splice_region_variant, synonymous_variant	Exon 4 of 182	ENST00000427231.7	NP_001157979.2
NEB	NM_001164508.2	c.78G>A	p.Glu26Glu	splice_region_variant, synonymous_variant	Exon 4 of 182	ENST00000397345.8	NP_001157980.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
NEB	ENST00000397345.8	c.78G>A	p.Glu26Glu	splice_region_variant, synonymous_variant	Exon 4 of 182	5	NM_001164508.2	ENSP00000380505.3
NEB	ENST00000427231.7	c.78G>A	p.Glu26Glu	splice_region_variant, synonymous_variant	Exon 4 of 182	5	NM_001164507.2	ENSP00000416578.2
NEB	ENST00000409198.5	c.78G>A	p.Glu26Glu	splice_region_variant, synonymous_variant	Exon 4 of 150	5		ENSP00000386259.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Nemaline myopathy 2 Uncertain:1

Oct 05, 2017

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change affects codon 26 of the NEB mRNA. It is a 'silent' change, meaning that it does not change the encoded amino acid sequence of the NEB protein. This variant also falls at the last nucleotide of exon 4 of the NEB coding sequence, which is part of the consensus splice site for this exon. Nucleotide substitutions within the consensus splice site are relatively common causes of aberrant splicing (PMID: 17576681, 9536098). This variant is not present in population databases (ExAC no frequency). This variant has not been reported in the literature in individuals with NEB-related disease. Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site, but this prediction has not been confirmed by published transcriptional studies. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.28
CADD	Benign	22
DANN	Benign	0.81
PhyloP100		3.9
Mutation Taster		=23/77	disease causing

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.91
SpliceAI score (max)		0.80		Details are displayed if max score is > 0.2
DS_DL_spliceai		0.80		Position offset: 0

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

Other links and lift over

dbSNP: rs1553702617; hg19: chr2-152586129;