chr1-154172972-G-C

Position:

chr1-154172972-G-C

Variant summary

Our verdict is Pathogenic. Variant got 17 ACMG points: 17P and 0B. PM1PM2PM5PP2PP3_ModeratePP5_Very_Strong

The NM_152263.4(TPM3):c.502C>G(p.Arg168Gly) variant causes a missense change involving the alteration of a 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 Likely pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R168C) has been classified as Pathogenic.

Frequency

Genomes: not found (cov: 32)

Consequence

TPM3
NM_152263.4 missense

Scores

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:5O:2

Conservation

PhyloP100: 8.06

Variant links:

Genes affected

TPM3 (HGNC:12012): (tropomyosin 3) This gene encodes a member of the tropomyosin family of actin-binding proteins. Tropomyosins are dimers of coiled-coil proteins that provide stability to actin filaments and regulate access of other actin-binding proteins. Mutations in this gene result in autosomal dominant nemaline myopathy and other muscle disorders. This locus is involved in translocations with other loci, including anaplastic lymphoma receptor tyrosine kinase (ALK) and neurotrophic tyrosine kinase receptor type 1 (NTRK1), which result in the formation of fusion proteins that act as oncogenes. There are numerous pseudogenes for this gene on different chromosomes. Alternative splicing results in multiple transcript variants. [provided by RefSeq, May 2013]

TPM3 links:

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ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 17 ACMG points.

PM1

In a chain Tropomyosin alpha-3 chain (size 283) in uniprot entity TPM3_HUMAN there are 32 pathogenic changes around while only 1 benign (97%) in NM_152263.4

PM2

Very rare variant in population databases, with high coverage;

PM5

Other missense variant is known to change same aminoacid residue: Variant chr1-154172972-G-A is described in Lovd as [Pathogenic].

PP2

Missense variant in gene, where missense usually causes diseases (based on misZ statistic), TPM3. . Gene score misZ 2.3546 (greater than the threshold 3.09). Trascript score misZ 3.2484 (greater than threshold 3.09). GenCC has associacion of gene with congenital generalized hypercontractile muscle stiffness syndrome, intermediate nemaline myopathy, congenital myopathy 4B, autosomal recessive, cap myopathy, congenital fiber-type disproportion myopathy, congenital myopathy 4A, autosomal dominant, TPM3-related myopathy, childhood-onset nemaline myopathy.

PP3

MetaRNN computational evidence supports a deleterious effect, 0.916

PP5

Variant 1-154172972-G-C is Pathogenic according to our data. Variant chr1-154172972-G-C is described in ClinVar as [Likely_pathogenic]. Clinvar id is 12453.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr1-154172972-G-C is described in Lovd as [Pathogenic]. Variant chr1-154172972-G-C is described in Lovd as [Likely_pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
TPM3	NM_152263.4 linkuse as main transcript	c.502C>G	p.Arg168Gly	missense_variant	5/10	ENST00000651641.1	NP_689476.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
TPM3	ENST00000651641.1 linkuse as main transcript	c.502C>G	p.Arg168Gly	missense_variant	5/10		NM_152263.4	ENSP00000498577	P1	P06753-1

Frequencies

GnomAD3 genomes

Cov.:

GnomAD4 exome

Cov.:

GnomAD4 genome

Cov.:

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:5Other:2

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not provided

Pathogenic:1Other:1

not provided, no classification provided	literature only	TPM3 homepage - Leiden Muscular Dystrophy pages	-	- -
Pathogenic, criteria provided, single submitter	clinical testing	GeneDx	Apr 27, 2017	The R168G variant in the TPM3 gene has been reported previously in an individual with congenital fiber type disproportion (Clarke et al., 2008). Functional studies of the R168G variant indicate a decreased affinity for actin and reduced calcium-induced ATPase activation (Robaszkiewicz et al., 2012; Yuen et al., 2015). Different missense variants in the same codon (R168C, R168H) have been reported in association with TPM3-related disorders (Clarke et al., 2008; Waddell et al., 2010; Marttila et al., 2014). The R168G variant is not observed in large population cohorts (Lek et al., 2016; 1000 Genomes Consortium et al., 2015; Exome Variant Server). The R168G variant is a non-conservative amino acid substitution, which is likely to impact secondary protein structure as these residues differ in polarity, charge, size and/or other properties. This substitution occurs at a position that is conserved across species. -

Congenital myopathy with fiber type disproportion;C5829889:Congenital myopathy 4B, autosomal recessive

Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Apr 12, 2023

For these reasons, this variant has been classified as Pathogenic. This variant disrupts the p.Arg168 amino acid residue in TPM3. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 12467750, 17376686, 18300303, 20554445, 24095155, 24692096). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. Experimental studies have shown that this missense change affects TPM3 function (PMID: 22749829). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is expected to disrupt TPM3 protein function. ClinVar contains an entry for this variant (Variation ID: 12453). This missense change has been observed in individuals with clinical features of autosomal dominant congenital myopathy and/or congenital fiber type disproportion (PMID: 18300303, 27854218; Invitae). This variant is not present in population databases (gnomAD no frequency). This sequence change replaces arginine, which is basic and polar, with glycine, which is neutral and non-polar, at codon 168 of the TPM3 protein (p.Arg168Gly). -

Congenital myopathy 4A, autosomal dominant

Pathogenic:1

Pathogenic, no assertion criteria provided

literature only

OMIM

Mar 01, 2008

- -

TPM3-related core myopathy

Pathogenic:1

Pathogenic, criteria provided, single submitter

research

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

Mar 01, 2024

PS3+PM1+PM2+PM5+PM6+PP2+PP3 -

Congenital myopathy 4B, autosomal recessive

Pathogenic:1

Likely pathogenic, criteria provided, single submitter

research

Center for Genetic Medicine Research, Children's National Medical Center

Dec 01, 2015

- -

Congenital myopathy with fiber type disproportion

Other:1

not provided, no classification provided

literature only

GeneReviews

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.99

BayesDel_addAF

Pathogenic

0.57

BayesDel_noAF

Pathogenic

0.58

CADD

Pathogenic

DANN

Uncertain

1.0

DEOGEN2

Uncertain

0.57

D;.;.;D;.;.;.;.;.;.;D

Eigen

Uncertain

0.45

Eigen_PC

Uncertain

0.52

FATHMM_MKL

Pathogenic

0.98

LIST_S2

Benign

0.71

T;T;T;T;.;T;T;T;T;T;T

M_CAP

Uncertain

0.24

MetaRNN

Pathogenic

0.92

D;D;D;D;D;D;D;D;D;D;D

MetaSVM

Pathogenic

1.1

MutationAssessor

Pathogenic

3.6

.;.;.;.;.;.;.;.;.;.;H

MutationTaster

Benign

1.0

D;D;D;D;D;D;D;D;D;D

PrimateAI

Pathogenic

0.85

PROVEAN

Pathogenic

-5.4

.;D;D;D;.;D;D;D;D;D;D

REVEL

Pathogenic

0.93

Sift

Uncertain

0.022

.;D;D;D;.;D;D;D;D;D;D

Sift4G

Uncertain

0.046

D;D;D;D;D;D;D;T;D;D;D

Polyphen

0.0020

.;B;.;.;.;.;.;.;B;.;.

Vest4

0.96

MVP

0.99

MPC

1.5

ClinPred

0.99

GERP RS

5.1

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.1

Varity_R

0.91

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.040

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

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over