chr15-63042830-A-G

Variant summary

Our verdict is Likely benign. The variant received -3 ACMG points: 1P and 4B. PVS1_SupportingBS2

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

6
8
2

Clinical Significance

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

Conservation

PhyloP100: 8.98

Publications

2 publications found
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-AS (HGNC:53635): (TPM1 antisense RNA)

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_benign. The variant received -3 ACMG points.

PVS1
Start lost variant, no pathogenic variants between lost start and next in-frame start position. Next in-frame start position is after 8 codons. Genomic position: 63042851. Lost 0.026 part of the original CDS.
BS2
High AC in GnomAdExome4 at 12 AD gene.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
TPM1NM_001018005.2 linkc.1A>G p.Met1? start_lost Exon 1 of 10 ENST00000403994.9 NP_001018005.1 P09493-1D9YZV4

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
TPM1ENST00000403994.9 linkc.1A>G p.Met1? start_lost Exon 1 of 10 1 NM_001018005.2 ENSP00000385107.4 P09493-1

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152132
Hom.:
0
Cov.:
33
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:
12
AN:
1460366
Hom.:
0
Cov.:
31
AF XY:
0.00000688
AC XY:
5
AN XY:
726612
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33426
American (AMR)
AF:
0.00
AC:
0
AN:
44674
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26074
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39640
South Asian (SAS)
AF:
0.0000348
AC:
3
AN:
86226
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53290
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5740
European-Non Finnish (NFE)
AF:
0.00000810
AC:
9
AN:
1111002
Other (OTH)
AF:
0.00
AC:
0
AN:
60294
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.521
Heterozygous variant carriers
0
1
2
3
4
5
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
GnomAD4 genome
AF:
0.00000657
AC:
1
AN:
152132
Hom.:
0
Cov.:
33
AF XY:
0.00
AC XY:
0
AN XY:
74316
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41438
American (AMR)
AF:
0.00
AC:
0
AN:
15290
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5176
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4832
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10610
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
67996
Other (OTH)
AF:
0.00
AC:
0
AN:
2092
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.475
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
Alfa
AF:
0.00
Hom.:
0
Bravo
AF:
0.00000378
ESP6500AA
AF:
0.00
AC:
0
ESP6500EA
AF:
0.000116
AC:
1
ExAC
AF:
0.00000825
AC:
1
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
May 03, 2022
Fulgent Genetics, Fulgent Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

not provided Uncertain:1
Oct 03, 2019
GeneDx
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

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
Apr 10, 2023
All of Us Research Program, National Institutes of Health
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

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
Feb 22, 2019
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

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
D
BayesDel_noAF
Pathogenic
0.59
CADD
Pathogenic
27
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
D
LIST_S2
Uncertain
0.90
D;D;D;.;D;D;D;D;D;D;D
M_CAP
Pathogenic
0.98
D
MetaRNN
Pathogenic
0.89
D;D;D;D;D;D;D;D;D;D;D
MetaSVM
Pathogenic
1.0
D
PhyloP100
9.0
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
D
GERP RS
4.5
PromoterAI
-0.36
Neutral
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.7
Varity_R
0.92
gMVP
0.95
Mutation Taster
=18/182
disease causing

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

Other links and lift over

dbSNP: rs367543668; hg19: chr15-63335029; API