2-151565144-TTTACC-T

Position:

• chr2-151565144-TTTACC-T

Variant summary

Our verdict is Pathogenic. Variant got 12 ACMG points: 12P and 0B. PVS1 PM2 PP5_Moderate

The NM_001164508.2(NEB):​c.18367-1_18370delGGTAA​(p.Val6123fs) variant causes a frameshift, splice acceptor, splice region, intron change. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Likely pathogenic (★). Variant results in nonsense mediated mRNA decay.

• Frequency: Genomes: not found (cov: 32)
• Consequence: NEB NM_001164508.2 frameshift, splice_acceptor, splice_region, intron
• Clinical Significance: Likely pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 5.93

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]

ACMG classification

Verdict is Pathogenic. Variant got 12 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 2-151565144-TTTACC-T is Pathogenic according to our data. Variant chr2-151565144-TTTACC-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 465517.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
NEB	NM_001164507.2	c.18367-1_18370delGGTAA	p.Val6123fs	frameshift_variant, splice_acceptor_variant, splice_region_variant, intron_variant	117/182	ENST00000427231.7	NP_001157979.2
NEB	NM_001164508.2	c.18367-1_18370delGGTAA	p.Val6123fs	frameshift_variant, splice_acceptor_variant, splice_region_variant, intron_variant	117/182	ENST00000397345.8	NP_001157980.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
NEB	ENST00000397345.8	c.18367-1_18370delGGTAA	p.Val6123fs	frameshift_variant, splice_acceptor_variant, splice_region_variant, intron_variant	117/182	5	NM_001164508.2	ENSP00000380505.3
NEB	ENST00000427231.7	c.18367-1_18370delGGTAA	p.Val6123fs	frameshift_variant, splice_acceptor_variant, splice_region_variant, intron_variant	117/182	5	NM_001164507.2	ENSP00000416578.2

Frequencies

GnomAD3 genomes Cov.: 32

We have no GnomAD4 exomes data on this position. Probably position not covered by the project.

GnomAD4 genome Cov.: 32

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

Nemaline myopathy 2 Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Aug 22, 2016

While this particular variant has not been reported in the literature, truncating variants in NEB are known to be pathogenic (PMID: 25205138). For these reasons, this variant has been classified as Likely Pathogenic. Nucleotide substitutions within the consensus splice site are relatively common causes of aberrant splicing (PMID: 17576681, 9536098). Algorithms developed to predict the effect of nucleotide changes on RNA splicing suggest that this variant may alter RNA splicing, but this prediction has not been confirmed by published transcriptional studies. While this variant is not present in population databases, the frequency information is unreliable, as metrics indicate poor data quality at this position in the ExAC database. This variant has not been reported in the literature in an individual with a NEB-related disease. This sequence change affects an acceptor splice site in intron 116 of the NEB gene. It is expected to disrupt RNA splicing and likely results in an absent or disrupted protein product. -

Computational scores

Source: dbNSFP v4.3

Splicing

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

Publications

LitVar

Other links and lift over

dbSNP: rs1553770146; hg19: chr2-152421658;