2-151606669-A-C

Position:

• chr2-151606669-A-C

Variant summary

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

The NM_001164507.2(NEB):​c.12684T>G​(p.Tyr4228Ter) variant causes a stop gained change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Pathogenic (★). Variant results in nonsense mediated mRNA decay.

• Frequency: Genomes: not found (cov: 14)
• Consequence: NEB NM_001164507.2 stop_gained
• Clinical Significance: Pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: -0.0400

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 2-151606669-A-C is Pathogenic according to our data. Variant chr2-151606669-A-C is described in ClinVar as [Pathogenic]. Clinvar id is 465462.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
NEB	NM_001164507.2	c.12684T>G	p.Tyr4228Ter	stop_gained	84/182	ENST00000427231.7
NEB	NM_001164508.2	c.12684T>G	p.Tyr4228Ter	stop_gained	84/182	ENST00000397345.8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
NEB	ENST00000397345.8	c.12684T>G	p.Tyr4228Ter	stop_gained	84/182	5	NM_001164508.2	P5
NEB	ENST00000427231.7	c.12684T>G	p.Tyr4228Ter	stop_gained	84/182	5	NM_001164507.2	A2
NEB	ENST00000409198.5	c.11601+3140T>G		intron_variant		5

Frequencies

GnomAD3 genomes Cov.: 14

GnomAD4 exome Cov.: 26

GnomAD4 genome Cov.: 14

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

Nemaline myopathy 2 Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Oct 04, 2022

For these reasons, this variant has been classified as Pathogenic. ClinVar contains an entry for this variant (Variation ID: 465462). This variant has not been reported in the literature in individuals affected with NEB-related conditions. The frequency data for this variant in the population databases (gnomAD) is considered unreliable due to the presence of homologous sequence, such as pseudogenes or paralogs, in the genome. This sequence change creates a premature translational stop signal (p.Tyr4228*) in the NEB gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in NEB are known to be pathogenic (PMID: 25205138). This variant occurs in a region of NEB (Exons 82-105) consisting of three highly homologous 8-exon repeat units (exons 82-89, exons 90-97, exons 98-105). Sequence variants in this region can be detected, but this assay cannot determine which of the three repeat units is affected, and zygosity is often ambiguous. All variants in this region are reported relative to the exon 82-89 repeat. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Pathogenic	0.51
CADD	Pathogenic	27
DANN	Benign	0.97
Eigen	Benign	-0.046
Eigen_PC	Benign	-0.32
FATHMM_MKL	Benign	0.58	D
MutationTaster	Benign	1.0	A;A;D;D
Vest4		0.81
GERP RS		-3.1

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.0		Details are displayed if max score is > 0.2

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

Publications

LitVar

Other links and lift over

dbSNP: rs1553875421; hg19: chr2-152463183;