2-151727791-G-A

Position:

• chr2-151727791-G-A

Variant summary

Our verdict is Benign. Variant got -7 ACMG points: 0P and 7B. BP4 BP6 BS1 BS2_Supporting

The NM_001164507.2(NEB):​c.194C>T​(p.Pro65Leu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000147 in 1,613,694 control chromosomes in the GnomAD database, including 3 homozygotes. In-silico tool predicts a benign outcome for this variant. 13/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Synonymous variant affecting the same amino acid position (i.e. P65P) has been classified as Likely benign.

• Frequency:
  • Genomes: 𝑓 0.000098 (0 hom., cov: 33)
  • Exomes 𝑓: 0.00015 (3 hom.)
• Consequence: NEB NM_001164507.2 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:7 B:2 O:1
• Conservation: PhyloP100: 2.39

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 Benign. Variant got -7 ACMG points.

• BP4: Computational evidence support a benign effect (MetaRNN=0.29076654).
• BP6: Variant 2-151727791-G-A is Benign according to our data. Variant chr2-151727791-G-A is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 229041.We mark this variant Likely_benign, oryginal submissions are: {not_provided=1, Likely_benign=2, Uncertain_significance=6}.
• BS1: Variant frequency is greater than expected in population mid. gnomad4_exome allele frequency = 0.000152 (222/1461406) while in subpopulation MID AF= 0.0108 (62/5756). AF 95% confidence interval is 0.00862. There are 3 homozygotes in gnomad4_exome. There are 124 alleles in male gnomad4_exome subpopulation. Median coverage is 31. This position pass quality control queck.
• BS2: High Homozygotes in GnomAdExome4 at 3 AR geneVariant has number of homozygotes lower than other variant known as pathogenic in the gene, so the strength is limited to Supporting.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
NEB	NM_001164507.2	c.194C>T	p.Pro65Leu	missense_variant	5/182	ENST00000427231.7
NEB	NM_001164508.2	c.194C>T	p.Pro65Leu	missense_variant	5/182	ENST00000397345.8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
NEB	ENST00000397345.8	c.194C>T	p.Pro65Leu	missense_variant	5/182	5	NM_001164508.2	P5
NEB	ENST00000427231.7	c.194C>T	p.Pro65Leu	missense_variant	5/182	5	NM_001164507.2	A2
NEB	ENST00000409198.5	c.194C>T	p.Pro65Leu	missense_variant	5/150	5

Frequencies

GnomAD3 genomes AF: 0.0000986 AC: 15 AN: 152170 Hom.: 0 Cov.: 33

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.000131

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.000207

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.000162

Gnomad OTH AF: 0.000478

GnomAD3 exomes AF: 0.000125 AC: 31 AN: 248882 Hom.: 0 AF XY: 0.000141 AC XY: 19 AN XY: 135016

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000291

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.000163

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.000186

Gnomad OTH exome AF: 0.000663

GnomAD4 exome AF: 0.000152 AC: 222 AN: 1461406 Hom.: 3 Cov.: 31 AF XY: 0.000171 AC XY: 124 AN XY: 726982

Gnomad4 AFR exome AF: 0.0000598

Gnomad4 AMR exome AF: 0.0000224

Gnomad4 ASJ exome AF: 0.0000383

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.000185

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.000114

Gnomad4 OTH exome AF: 0.000215

GnomAD4 genome AF: 0.0000985 AC: 15 AN: 152288 Hom.: 0 Cov.: 33 AF XY: 0.000107 AC XY: 8 AN XY: 74470

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.000131

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.000207

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.000162

Gnomad4 OTH AF: 0.000473

Alfa AF: 0.000147 Hom.: 0

Bravo AF: 0.000140

TwinsUK AF: 0.000270 AC: 1

ALSPAC AF: 0.00 AC: 0

ESP6500AA AF: 0.00 AC: 0

ESP6500EA AF: 0.000241 AC: 2

ExAC AF: 0.000141 AC: 17

EpiCase AF: 0.000491

EpiControl AF: 0.000237

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:7 Benign:2 Other:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Nemaline myopathy 2 Uncertain:3 Benign:1 Other:1

Uncertain significance, criteria provided, single submitter	clinical testing	Genome-Nilou Lab	May 18, 2021	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Counsyl	Jan 06, 2017	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Illumina Laboratory Services, Illumina	Jan 12, 2018	This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -
not provided, no classification provided	phenotyping only	GenomeConnect, ClinGen	-	Variant interpreted as Uncertain significance and reported on 10-03-2020 by Lab or GTR ID 500031. GenomeConnect assertions are reported exactly as they appear on the patient-provided report from the testing laboratory. GenomeConnect staff make no attempt to reinterpret the clinical significance of the variant. -
Likely benign, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Jan 29, 2024	- -

not specified Uncertain:2 Benign:1

Likely benign, criteria provided, single submitter	clinical testing	GeneDx	Feb 28, 2018	This variant is considered likely benign or benign based on one or more of the following criteria: it is a conservative change, it occurs at a poorly conserved position in the protein, it is predicted to be benign by multiple in silico algorithms, and/or has population frequency not consistent with disease. -
Uncertain significance, criteria provided, single submitter	clinical testing	Women's Health and Genetics/Laboratory Corporation of America, LabCorp	May 09, 2023	Variant summary: NEB c.194C>T (p.Pro65Leu) results in a non-conservative amino acid change in the encoded protein sequence. Two of four in-silico tools predict a benign effect of the variant on protein function. The variant allele was found at a frequency of 0.00012 in 248882 control chromosomes. This frequency is not significantly higher than estimated for a pathogenic variant in NEB causing Nemaline Myopathy 2 (0.00012 vs 0.0035), allowing no conclusion about variant significance. c.194C>T has been reported in the literature in individuals affected Myopathies (Zenagui_2018, Morales_2021) without strong evidence for causality. These reports do not provide unequivocal conclusions about association of the variant with Nemaline Myopathy 2. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. Seven clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. The following publications have been ascertained in the context of this evaluation (PMID: 34440373, 29792937). Multiple laboratories reported the variant with conflicting assessments: VUS (n=5) and Likely Benign (n=2) . Based on the evidence outlined above, the variant was classified as uncertain significance. -
Uncertain significance, criteria provided, single submitter	clinical testing	Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine	Mar 03, 2016	The p.Pro65Leu variant in NEB has not been previously reported in individuals wi th myopathy, but has been identified in 12/66624 European chromosomes by the Exo me Aggregation Consortium (ExAC, http://exac.broadinstitute.org; dbSNP rs3759090 06). Computational prediction tools and conservation analysis do not provide str ong support for or against an impact to the protein. In summary, the clinical si gnificance of the p.Pro65Leu is uncertain. -

NEB-related disorder Uncertain:1

Uncertain significance, no assertion criteria provided

clinical testing

PreventionGenetics, part of Exact Sciences

Jun 12, 2024

The NEB c.194C>T variant is predicted to result in the amino acid substitution p.Pro65Leu. This variant was reported in a cohort study of individuals with neuromuscular disorders (Zenagui et al 2018. PubMed ID: 29792937). This variant was also reported with a second NEB variant in an individual with a milder adult-onset myopathy (Juntas Morales R et al 2021. PubMed ID: 34440373). This variant is reported in 0.018% of alleles in individuals of European (non-Finnish) descent in gnomAD. At this time, the clinical significance of this variant is uncertain due to the absence of conclusive functional and genetic evidence. -

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Revvity Omics, Revvity

Jan 17, 2023

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.12
BayesDel_addAF	Benign	-0.33	T
BayesDel_noAF	Benign	-0.42
CADD	Benign	22
DANN	Uncertain	1.0
DEOGEN2	Benign	0.030	.;.;T;.;T;.;.
Eigen	Uncertain	0.34
Eigen_PC	Uncertain	0.45
FATHMM_MKL	Uncertain	0.95	D
LIST_S2	Uncertain	0.86	D;D;D;D;D;.;.
M_CAP	Benign	0.026	D
MetaRNN	Benign	0.29	T;T;T;T;T;T;T
MetaSVM	Benign	-0.98	T
MutationAssessor	Benign	0.69	N;N;.;N;N;N;N
MutationTaster	Benign	0.83	D;D;D;D
PrimateAI	Benign	0.47	T
PROVEAN	Benign	-1.8	N;N;.;N;N;.;.
REVEL	Benign	0.12
Sift	Pathogenic	0.0	D;D;.;D;D;.;.
Sift4G	Uncertain	0.021	D;D;D;D;D;D;D
Polyphen		0.90	.;.;.;.;P;.;.
Vest4		0.42
MVP		0.55
MPC		0.35
ClinPred		0.13	T
GERP RS		5.9
Varity_R		0.25
gMVP		0.23

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: rs375909006; hg19: chr2-152584305;