15-63042830-A-G

Position:

chr15-63042830-A-G

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 8P and 4B. PVS1BS2

The NM_001018005.2(TPM1):c.1A>G(p.Met1?) variant causes a start lost change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000806 in 1,612,498 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 33)

Exomes 𝑓: 0.0000082 ( 0 hom. )

Consequence

TPM1
NM_001018005.2 start_lost

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:4

Conservation

PhyloP100: 8.98

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 Uncertain_significance. Variant got 4 ACMG points.

PVS1

Start lost variant, no new inframe start found.

BS2

High AC in GnomAdExome4 at 12 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
TPM1	NM_001018005.2 linkuse as main transcript	c.1A>G	p.Met1?	start_lost	1/10	ENST00000403994.9	NP_001018005.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
TPM1	ENST00000403994.9 linkuse as main transcript	c.1A>G	p.Met1?	start_lost	1/10	1	NM_001018005.2	ENSP00000385107	A1	P09493-1

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152132

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

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:

0.0000147

Gnomad OTH

AF:

0.00

GnomAD4 exome

AF:

0.00000822

AC:

AN:

1460366

Hom.:

Cov.:

AF XY:

0.00000688

AC XY:

AN XY:

726612

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.0000348

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00000810

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

AF:

0.00000657

AC:

AN:

152132

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

74316

show subpopulations

Gnomad4 AFR

AF:

0.00

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:

0.0000147

Gnomad4 OTH

AF:

0.00

Bravo

AF:

0.00000378

ESP6500AA

AF:

0.00

AC:

ESP6500EA

AF:

0.000116

AC:

ExAC

AF:

0.00000825

AC:

EpiCase

AF:

0.0000545

EpiControl

AF:

0.00

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:4

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Hypertrophic cardiomyopathy 3;C2678476:Dilated cardiomyopathy 1Y

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Fulgent Genetics, Fulgent Genetics

May 03, 2022

- -

not provided

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

GeneDx

Oct 03, 2019

Has not been previously published as pathogenic or benign to our knowledge; Not observed in large population cohorts (Lek et al., 2016); Alters the initiator methionine codon, and the resultant protein would be described as "p.Met1?" using a question mark to signify that it is not known if the loss of Met1 means that all protein translation is completely prevented or if an abnormal protein is produced using an alternate methionine; Initiation codon variant in a gene for which loss-of-function is not a known mechanism of disease; Another variant that affects in the initiator methionine codon (c.2delT) has been reported in an individual referred for DCM genetic testing (Walsh et al., 2017); however, the pathogenicity of this variant has not been definitively determined -

Hypertrophic cardiomyopathy

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

All of Us Research Program, National Institutes of Health

Apr 10, 2023

This variant alters the translation initiation codon methionine at codon 1 of the TPM1 protein. This variant is expected to disrupt translation initiation and result in an absent or truncated protein product. To our knowledge, functional studies have not been reported for this variant. This variant has not been reported in individuals affected with TPM1-related disorders in the literature. This variant has not been identified in the general population by the Genome Aggregation Database (gnomAD). Clinical relevance of loss-of-function TPM1 truncation variants in autosomal dominant cardiovascular disorders is not clearly established. The available evidence is insufficient to determine the role of this variant in disease conclusively. Therefore, this variant is classified as a Variant of Uncertain Significance. -

Cardiovascular phenotype

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Feb 22, 2019

The p.M1? variant (also known as c.1A>G), located in coding exon 1 of the TPM1 gene, results from an A to G substitution at nucleotide position 1. This alters the methionine residue at the initiation codon. Variations that modify the initiation codon (ATG) are expected to result in either loss of translation initiation, N-terminal truncation, or cause a shift in the mRNA reading frame; however there are two alternate in-frame methionines 7 and 9 amino acids from the initiation site and the significance of the N-terminus for this protein is not well established. This amino acid position is highly conserved in available vertebrate species. Since supporting evidence is limited at this time, the clinical significance of p.M1? remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_addAF

Pathogenic

0.57

BayesDel_noAF

Pathogenic

0.59

CADD

Pathogenic

DANN

Uncertain

0.99

DEOGEN2

Uncertain

0.62

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

Eigen

Uncertain

0.63

Eigen_PC

Uncertain

0.61

FATHMM_MKL

Uncertain

0.92

LIST_S2

Uncertain

0.90

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

M_CAP

Pathogenic

0.98

MetaRNN

Pathogenic

0.89

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

MetaSVM

Pathogenic

1.0

MutationTaster

Benign

0.93

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

PROVEAN

Benign

-1.9

N;N;.;D;N;N;N;N;N;.;.

REVEL

Pathogenic

0.93

Sift

Uncertain

0.0010

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

Sift4G

Uncertain

0.0020

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

Polyphen

1.0, 0.99, 1.0

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

Vest4

0.94

MVP

0.99

ClinPred

0.99

GERP RS

4.5

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.7

Varity_R

0.92

gMVP

0.95

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

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