rs371934474

Variant names:

Variant summary

Our verdict is Benign. Variant got -8 ACMG points: 3P and 11B. PM1PP2BP4_ModerateBP6BS1BS2

The NM_001018005.2(TPM1):c.797A>G(p.Lys266Arg) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000366 in 1,614,132 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

Frequency

Genomes: 𝑓 0.00020 ( 0 hom., cov: 33)

Exomes 𝑓: 0.000020 ( 0 hom. )

Consequence

TPM1
NM_001018005.2 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:4B:4

Conservation

PhyloP100: 9.32

Variant links:

Genes affected

TPM1 (HGNC:12010): (tropomyosin 1) This gene is a member of the tropomyosin family of highly conserved, widely distributed actin-binding proteins involved in the contractile system of striated and smooth muscles and the cytoskeleton of non-muscle cells. Tropomyosin is composed of two alpha-helical chains arranged as a coiled-coil. It is polymerized end to end along the two grooves of actin filaments and provides stability to the filaments. The encoded protein is one type of alpha helical chain that forms the predominant tropomyosin of striated muscle, where it also functions in association with the troponin complex to regulate the calcium-dependent interaction of actin and myosin during muscle contraction. In smooth muscle and non-muscle cells, alternatively spliced transcript variants encoding a range of isoforms have been described. Mutations in this gene are associated with type 3 familial hypertrophic cardiomyopathy and dilated cardiomyopathy 1Y. [provided by RefSeq, Jun 2022]

TPM1 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Benign. Variant got -8 ACMG points.

PM1

In a chain Tropomyosin alpha-1 chain (size 283) in uniprot entity TPM1_HUMAN there are 61 pathogenic changes around while only 1 benign (98%) in NM_001018005.2

PP2

Missense variant in the TPM1 gene, where missense mutations are typically associated with disease (based on misZ statistic). The gene has 42 curated pathogenic missense variants (we use a threshold of 10). The gene has 25 curated benign missense variants. Gene score misZ: 2.8677 (below the threshold of 3.09). Trascript score misZ: 3.9402 (above the threshold of 3.09). GenCC associations: The gene is linked to dilated cardiomyopathy, left ventricular noncompaction, hypertrophic cardiomyopathy, hypertrophic cardiomyopathy 3, arrhythmogenic right ventricular cardiomyopathy, familial isolated dilated cardiomyopathy, dilated cardiomyopathy 1Y.

BP4

Computational evidence support a benign effect (MetaRNN=0.21356535).

BP6

Variant 15-63064088-A-G is Benign according to our data. Variant chr15-63064088-A-G is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 178148.We mark this variant Likely_benign, oryginal submissions are: {Likely_benign=4, Uncertain_significance=4}.

BS1

Variant frequency is greater than expected in population afr. gnomad4 allele frequency = 0.000197 (30/152328) while in subpopulation AFR AF= 0.000722 (30/41570). AF 95% confidence interval is 0.000519. There are 0 homozygotes in gnomad4. There are 15 alleles in male gnomad4 subpopulation. Median coverage is 33. This position pass quality control queck.

BS2

High AC in GnomAd4 at 30 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TPM1	NM_001018005.2 link	c.797A>G	p.Lys266Arg	missense_variant	Exon 9 of 10	ENST00000403994.9	NP_001018005.1	P09493-1D9YZV4

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TPM1	ENST00000403994.9 link	c.797A>G	p.Lys266Arg	missense_variant	Exon 9 of 10	1	NM_001018005.2	ENSP00000385107.4		P09493-1

Frequencies

GnomAD3 genomes

AF:

0.000197

AC:

AN:

152210

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.000724

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.00

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000517

AC:

AN:

251316

Hom.:

AF XY:

0.0000368

AC XY:

AN XY:

135836

show subpopulations

Gnomad AFR exome

AF:

0.000738

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.0000463

Gnomad NFE exome

AF:

0.00

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000198

AC:

AN:

1461804

Hom.:

Cov.:

AF XY:

0.0000179

AC XY:

AN XY:

727202

show subpopulations

Gnomad4 AFR exome

AF:

0.000627

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.0000749

Gnomad4 NFE exome

AF:

0.00

Gnomad4 OTH exome

AF:

0.0000662

GnomAD4 genome

AF:

0.000197

AC:

AN:

152328

Hom.:

Cov.:

AF XY:

0.000201

AC XY:

AN XY:

74496

show subpopulations

Gnomad4 AFR

AF:

0.000722

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.00

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.000225

Hom.:

Bravo

AF:

0.000181

ESP6500AA

AF:

0.000227

AC:

ESP6500EA

AF:

0.00

AC:

ExAC

AF:

0.0000412

AC:

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:4Benign:4

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

not specified

Uncertain:2

Jan 17, 2014

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The Lys266Arg variant in TPM1 has not been previously reported in any other fami lies with cardiomyopathy, but has been identified in 1/4406 African American chr omosomes by the NHLBI Exome Sequencing Project (http://evs.gs.washington.edu/EVS /). Computational analyses (biochemical amino acid properties, conservation, Ali gnGVGD, PolyPhen2, and SIFT) do not provide strong support for or against an imp act to the protein. Additional information is needed to fully assess the clinica l significance of this variant. -

Nov 19, 2018

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

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant summary: TPM1 c.797A>G (p.Lys266Arg) results in a conservative amino acid change in the encoded protein sequence. Three of five in-silico tools predict a benign effect of the variant on protein function. The variant allele was found at a frequency of 7.6e-05 in 277096 control chromosomes, predominantly within the African subpopulation at a frequency of 0.00083 in the gnomAD database. The observed variant frequency within African control individuals in the gnomAD database is approximately 11 fold of the estimated maximal expected allele frequency for a pathogenic variant in TPM1 causing Cardiomyopathy phenotype (7.5e-05), suggesting that the variant is a benign polymorphism found primarily in populations of African origin. c.797A>G has been reported in the literature in two individuals affected with Cardiomyopathy (Walsh 2017). These reports do not provide unequivocal conclusions about association of the variant with Cardiomyopathy. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. Two clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation, and both of them classified the variant as uncertain significance. Based on the evidence outlined above, the variant was classified as VUS-possibly benign. -

Cardiomyopathy

Benign:2

Mar 08, 2023

Color Diagnostics, LLC DBA Color Health

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Oct 28, 2020

CHEO Genetics Diagnostic Laboratory, Children's Hospital of Eastern Ontario

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

not provided

Uncertain:1

Mar 02, 2021

Mayo Clinic Laboratories, Mayo Clinic

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Left ventricular noncompaction

Uncertain:1

Jul 26, 2017

Molecular Diagnostic Laboratory for Inherited Cardiovascular Disease, Montreal Heart Institute

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Hypertrophic cardiomyopathy

Benign:1

Dec 22, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Cardiovascular phenotype

Benign:1

May 08, 2023

Ambry Genetics

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.088

CardioboostCm

Benign

0.024

BayesDel_addAF

Uncertain

0.070

BayesDel_noAF

Pathogenic

0.26

CADD

Pathogenic

DANN

Uncertain

1.0

DEOGEN2

Uncertain

0.79

.;D;.;.;.;D

Eigen

Benign

0.072

Eigen_PC

Uncertain

0.29

FATHMM_MKL

Pathogenic

0.97

LIST_S2

Uncertain

0.96

D;D;D;D;D;D

M_CAP

Uncertain

0.13

MetaRNN

Benign

0.21

T;T;T;T;T;T

MetaSVM

Uncertain

0.63

MutationAssessor

Benign

1.5

L;L;L;.;.;.

PROVEAN

Benign

-1.2

N;N;.;.;.;N

REVEL

Uncertain

0.48

Sift

Benign

0.042

D;D;.;.;.;T

Sift4G

Benign

0.36

T;T;.;.;.;T

Polyphen

0.0020, 0.0030

.;B;B;.;.;.

Vest4

0.74

MVP

0.97

ClinPred

0.14

GERP RS

5.8

Varity_R

0.21

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.13

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