NM_001164507.2:c.24189_24192dupTCAA

Variant names:

• chr2-151498274-C-CTTGA
• rs1553555882
• NM_001164507.2:c.24189_24192dupTCAA

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The NM_001164507.2(NEB):​c.24189_24192dupTCAA​(p.Glu8065SerfsTer5) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000572 in 1,399,232 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Likely pathogenic (★★). Variant results in nonsense mediated mRNA decay.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000057 (0 hom.)
• Consequence: NEB NM_001164507.2 frameshift
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:10
• Conservation: PhyloP100: 1.40

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]

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]

ACMG classification

Verdict is Pathogenic. Variant got 18 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 2-151498274-C-CTTGA is Pathogenic according to our data. Variant chr2-151498274-C-CTTGA is described in ClinVar as [Likely_pathogenic]. Clinvar id is 533994.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
NEB	NM_001164507.2	c.24189_24192dupTCAA	p.Glu8065SerfsTer5	frameshift_variant	Exon 170 of 182	ENST00000427231.7	NP_001157979.2
NEB	NM_001164508.2	c.24189_24192dupTCAA	p.Glu8065SerfsTer5	frameshift_variant	Exon 170 of 182	ENST00000397345.8	NP_001157980.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
NEB	ENST00000397345.8	c.24189_24192dupTCAA	p.Glu8065SerfsTer5	frameshift_variant	Exon 170 of 182	5	NM_001164508.2	ENSP00000380505.3
NEB	ENST00000427231.7	c.24189_24192dupTCAA	p.Glu8065SerfsTer5	frameshift_variant	Exon 170 of 182	5	NM_001164507.2	ENSP00000416578.2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000572 AC: 8 AN: 1399232 Hom.: 0 Cov.: 31 AF XY: 0.00000580 AC XY: 4 AN XY: 690130

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.0000840

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: 0.00000278

Gnomad4 OTH exome AF: 0.0000345

GnomAD4 genome Cov.: 32

Bravo AF: 0.0000113

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:10

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Nemaline myopathy 2 Pathogenic:5

May 04, 2022

Mendelics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

-

Consultorio y Laboratorio de Neurogenética, Hospital JM Ramos Mejia

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Jan 18, 2025

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change creates a premature translational stop signal (p.Glu8100Serfs*5) 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 is not present in population databases (gnomAD no frequency). This premature translational stop signal has been observed in individuals with nemaline myopathy (PMID: 12207938, 19805734, 26403434). ClinVar contains an entry for this variant (Variation ID: 533994). For these reasons, this variant has been classified as Pathogenic. -

Mar 01, 2024

Muscle and Diseases Team, Institut de Génétique et Biologie Moléculaire et Cellulaire

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: research

PVS1+PP1_Strong+PM2 -

Feb 01, 2024

Laboratory of Medical Genetics, National & Kapodistrian University of Athens

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: curation

- -

Nemaline myopathy Pathogenic:2

Nov 14, 2019

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

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant summary: NEB c.24294_24297dupTCAA (p.Glu8100SerfsX5) results in a premature termination codon, predicted to cause a truncation of the encoded protein or absence of the protein due to nonsense mediated decay, which are commonly known mechanisms for disease. Truncations downstream of this position have been classified as pathogenic by our laboratory. The variant was absent in 157122 control chromosomes (gnomAD). c.24294_24297dupTCAA has been reported in the literature in multiple compound heterozygote and homozygote individuals affected with Nemaline Myopathy 2 (Lehtokari_2014, Oliveira_2016, Pelin_2002). These data indicate that the variant is very likely to be associated with disease. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. A ClinVar submission (evaluation after 2014) cites the variant as pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic. -

Feb 26, 2025

Broad Center for Mendelian Genomics, Broad Institute of MIT and Harvard

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: curation

The p.Glu8065SerfsTer5 variant in NEB has been reported in at least four individuals with nemaline myopathy (PMID: 12207938, 33084218, 36233295), and has been identified in 0.006% (3/50984) of Latino/Admixed American chromosomes by the Genome Aggregation Database (gnomAD, http://gnomad.broadinstitute.org; dbSNP ID: rs1553555882). Although this variant has been seen in the general population in a heterozygous state, its frequency is low enough to be consistent with a recessive carrier frequency. This variant has also been reported in ClinVar (Variation ID: 533994) and has been interpreted as pathogenic by multiple submitters. Of the 4 affected individuals, 3 were compound heterozygotes that carried a reported pathogenic/likely pathogenic variant in trans or with unknown phase, which increases the likelihood that the p.Glu8065SerfsTer5variant is pathogenic (Variation ID: 1213189; PMID: 25205138, 35175440). This variant is predicted to cause a frameshift, which alters the protein’s amino acid sequence beginning at position 8065 and leads to a premature termination codon 5 amino acids downstream. This alteration is then predicted to lead to a truncated or absent protein. Computational tools predict a splicing impact, though this information is not predictive enough to determine/rule out pathogenicity. This variant is in an in-frame exon and is more likely to escape nonsense mediated decay (NMD) and result in a truncated protein. Loss of function of the NEB gene is an established disease mechanism in autosomal recessive nemaline myopathy. In summary, although additional studies are required to fully establish its clinical significance, this variant is likely pathogenic for autosomal recessive nemaline myopathy. ACMG/AMP Criteria applied: PVS1_strong, PM3, PM2_supporting (Richards 2015). -

See cases Pathogenic:1

Aug 20, 2020

Laboratorio de Genetica e Diagnostico Molecular, Hospital Israelita Albert Einstein

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

ACMG classification criteria: PVS1, PS4, PM2, PM3 -

not provided Pathogenic:1

Mar 10, 2022

GeneDx

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Reported in individuals with core-rod myopathy who also harbored a second NEB variant (Lehtokari et al., 2014; Malfatti et al., 2015); Frameshift variant predicted to result in protein truncation or nonsense mediated decay in a gene for which loss-of-function is a known mechanism of disease; Not observed at significant frequency in large population cohorts (gnomAD); This variant is associated with the following publications: (PMID: 33084218, 12207938, 26841830, 19805734, 25205138, 16917880, 26403434) -

Arthrogryposis multiplex congenita 6 Pathogenic:1

Feb 05, 2024

Baylor Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

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: rs1553555882; hg19: chr2-152354788;