2-151729614-C-T

Variant names:

• chr2-151729614-C-T
• rs778593702
• NM_001164507.2:c.78+1G>A

Variant summary

Our verdict is Pathogenic. The variant received 10 ACMG points: 10P and 0B. PVS1 PM3

This summary comes from the ClinGen Evidence Repository: The c.78+1G>A variant in NEB occurs within the canonical splice donor site +1 of intron 4. It is expected to disrupt RNA splicing of in-frame exon 4 leading to loss of protein function and loss-of-function of NEB is an established disease mechanism (PVS1). The highest population minor allele frequency in gnomAD v4.1.0 is 0.00007461 (88/1179410) in non-Finnish European which does not meet the threshold for PM2_Supporting (≤ 0.0000559). This variant has been detected in more than four unrelated affected individuals with a second pathogenic variant (PM3_Very Strong, Internal lab contributor: Invitae, SCV001578888.4; PMID:25205138, 30859559). In summary, this variant meets the criteria to be classified as pathogenic for autosomal recessive nemaline myopathy based on the ACMG/AMP criteria applied, as specified by the ClinGen Congenital Myopathies VCEP: PVS1_Strong, PM3_Very Strong (Congenital Myopathies VCEP specifications version 1; 8/7/2024). LINK:https://erepo.genome.network/evrepo/ui/classification/CA1912012/MONDO:0018958/146

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.000061 (0 hom.)
• Consequence: NEB NM_001164508.2 splice_donor, intron
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Pathogenic reviewed by expert panel P:10
• Conservation: PhyloP100: 3.89
• Publications: 3 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, Myriad Women's Health, Ambry Genetics, G2P, Labcorp Genetics (formerly Invitae)
• autosomal dominant nebulin-related myopathy

  Inheritance: AD Classification: MODERATE Submitted by: ClinGen
• 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

Specifications for NEB are available in the ClinGen Criteria Specification Registry and recommended for reference when assigning criteria.

Our verdict: Pathogenic. The variant received 10 ACMG points.

• PVS1: For more information check the summary or visit ClinGen Evidence Repository.
• PM3: For more information check the summary or visit ClinGen Evidence Repository.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_001164508.2. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	NEB	NM_001164507.2	MANE Plus Clinical	c.78+1G>A		splice_donor intron	N/A	NP_001157979.2	P20929-3
	NEB	NM_001164508.2	MANE Select	c.78+1G>A		splice_donor intron	N/A	NP_001157980.2	P20929-2
	NEB	NM_001271208.2		c.78+1G>A		splice_donor intron	N/A	NP_001258137.2

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	NEB	ENST00000397345.8	TSL:5 MANE Select	c.78+1G>A		splice_donor intron	N/A	ENSP00000380505.3	P20929-2
	NEB	ENST00000427231.7	TSL:5 MANE Plus Clinical	c.78+1G>A		splice_donor intron	N/A	ENSP00000416578.2	P20929-3
	NEB	ENST00000409198.5	TSL:5	c.78+1G>A		splice_donor intron	N/A	ENSP00000386259.1	P20929-4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD2 exomes AF: 0.00000804 AC: 2 AN: 248816 AF XY: 0.00000741

Gnomad AFR exome AF: 0.0000647

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000887

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000609 AC: 89 AN: 1461018 Hom.: 0 Cov.: 31 AF XY: 0.0000537 AC XY: 39 AN XY: 726822

African (AFR) AF: 0.00 AC: 0 AN: 33430

American (AMR) AF: 0.00 AC: 0 AN: 44676

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26102

East Asian (EAS) AF: 0.00 AC: 0 AN: 39692

South Asian (SAS) AF: 0.00 AC: 0 AN: 86250

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53352

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5764

European-Non Finnish (NFE) AF: 0.0000792 AC: 88 AN: 1111408

Other (OTH) AF: 0.0000166 AC: 1 AN: 60344

GnomAD4 genome Cov.: 32

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.0000189

EpiCase AF: 0.0000546

EpiControl AF: 0.0000593

ClinVar

ClinVar submissions

Significance: Pathogenic

Revision: reviewed by expert panel

Pathogenic	VUS	Benign	Condition
4	-	-	Nemaline myopathy 2 (4)
2	-	-	Nemaline myopathy (2)
1	-	-	Arthrogryposis multiplex congenita 6 (1)
1	-	-	NEB-related disorder (1)
1	-	-	Nemaline myopathy 2;C5543431:Arthrogryposis multiplex congenita 6 (1)
1	-	-	not provided (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.50	D
BayesDel_noAF	Pathogenic	0.28
CADD	Pathogenic	30
DANN	Uncertain	0.99
Eigen	Pathogenic	1.1
Eigen_PC	Pathogenic	0.93
FATHMM_MKL	Uncertain	0.82	D
PhyloP100		3.9
Mutation Taster		=0/100	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.93
SpliceAI score (max)		0.90		Details are displayed if max score is > 0.2
DS_DL_spliceai		0.90		Position offset: 1

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

MaxEntScan Visualizer can be used to analyze the impact of this mutation on the neighboring sequence.

Other links and lift over

dbSNP: rs778593702;

hg19: chr2-152586128;