ENST00000266732.8:c.909G>T

Variant summary

Our verdict is Likely benign. The variant received -6 ACMG points: 0P and 6B. BP4_ModerateBS2

The ENST00000266732.8(TMPO):​c.909G>T​(p.Met303Ile) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000496 in 1,614,018 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. M303V) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000046 ( 0 hom., cov: 33)
Exomes 𝑓: 0.000050 ( 0 hom. )

Consequence

TMPO
ENST00000266732.8 missense

Scores

2
17

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:5

Conservation

PhyloP100: 1.16

Publications

1 publications found
Variant links:
Genes affected
TMPO (HGNC:11875): (thymopoietin) Through alternative splicing, this gene encodes several distinct LEM domain containing protein isoforms. LEM domain proteins include inner nuclear membrane and intranuclear proteins, and are involved in a variety of cellular functions including gene expression, chromatin organization, and replication and cell cycle control. The encoded alpha isoform is broadly diffuse in the nucleus and contains a lamin binding domain, while the beta and gamma isoforms are localized to the nuclear membrane and contain an HDAC3 interaction domain. The distinct isoforms may compete with each other when acting to chaperone other proteins and regulate transcription. [provided by RefSeq, Aug 2019]
TMPO Gene-Disease associations (from GenCC):
  • familial isolated dilated cardiomyopathy
    Inheritance: AD Classification: SUPPORTIVE, NO_KNOWN Submitted by: ClinGen, Orphanet
  • dilated cardiomyopathy
    Inheritance: AD Classification: NO_KNOWN Submitted by: Ambry Genetics
  • hypertrophic cardiomyopathy
    Inheritance: AD Classification: NO_KNOWN Submitted by: ClinGen

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_benign. The variant received -6 ACMG points.

BP4
Computational evidence support a benign effect (MetaRNN=0.08523953).
BS2
High AC in GnomAd4 at 7 AD gene.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
TMPONM_001032283.3 linkc.565+1328G>T intron_variant Intron 3 of 8 ENST00000556029.6 NP_001027454.1 P42167-1A0A024RBE7Q59G12

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
TMPOENST00000556029.6 linkc.565+1328G>T intron_variant Intron 3 of 8 1 NM_001032283.3 ENSP00000450627.1 P42167-1

Frequencies

GnomAD3 genomes
AF:
0.0000460
AC:
7
AN:
152200
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:
0.000103
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000239
AC:
6
AN:
251310
AF XY:
0.0000221
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000528
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000499
AC:
73
AN:
1461818
Hom.:
0
Cov.:
32
AF XY:
0.0000495
AC XY:
36
AN XY:
727206
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33478
American (AMR)
AF:
0.00
AC:
0
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39700
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86258
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53352
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.0000585
AC:
65
AN:
1112006
Other (OTH)
AF:
0.000132
AC:
8
AN:
60396
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.474
Heterozygous variant carriers
0
5
11
16
22
27
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
4
8
12
16
20
<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:
0.0000460
AC:
7
AN:
152200
Hom.:
0
Cov.:
33
AF XY:
0.0000269
AC XY:
2
AN XY:
74364
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41456
American (AMR)
AF:
0.00
AC:
0
AN:
15284
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3468
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5204
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4830
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:
0.000103
AC:
7
AN:
68026
Other (OTH)
AF:
0.00
AC:
0
AN:
2094
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.461
Heterozygous variant carriers
0
1
1
2
2
3
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:
0.0000450
Hom.:
0
Bravo
AF:
0.0000529
ESP6500AA
AF:
0.00
AC:
0
ESP6500EA
AF:
0.000233
AC:
2
ExAC
AF:
0.0000165
AC:
2
EpiCase
AF:
0.000109
EpiControl
AF:
0.00

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:5
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not specified Uncertain:3
Apr 13, 2025
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The p.M303I variant (also known as c.909G>T), located in coding exon 4 of the TMPO gene, results from a G to T substitution at nucleotide position 909. The methionine at codon 303 is replaced by isoleucine, an amino acid with highly similar properties. This amino acid position is conserved. In addition, this alteration is predicted to be tolerated by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Dec 18, 2014
Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The p.Met303Ile variant in TMPO has been identified by our laboratory in 1 indiv idual with ischemic cardiomyopathy. This variant has also been identified in 2/6 7574 European chromosomes by the Exome Aggregation Consortium (ExAC, http://exac .broadinstitute.org; dbSNP rs369208265). Methionine (Met) at position 303 is not conserved in mammals or evolutionarily distant species and 1 mammal (squirrel m onkey) carries an isoleucine (Ile) at this position, raising the possibility tha t this change may be tolerated. Additional computational prediction tools also s uggest that the p.Met303Ile variant may not impact the protein, though this info rmation is not predictive enough to rule out pathogenicity. In summary, the clin ical significance of the p.Met303Ile variant is uncertain. -

Dec 09, 2024
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

not provided Uncertain:1
Nov 15, 2022
GeneDx
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

In silico analysis supports that this missense variant does not alter protein structure/function; Has not been previously published as pathogenic or benign in association with cardiomyopathy or other TMPO-related disorders to our knowledge; This variant is associated with the following publications: (PMID: 28404951) -

Loeys-Dietz syndrome 2 Uncertain:1
Jan 01, 2025
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces methionine, which is neutral and non-polar, with isoleucine, which is neutral and non-polar, at codon 303 of the TMPO protein (p.Met303Ile). This variant is present in population databases (rs369208265, gnomAD 0.005%). This variant has not been reported in the literature in individuals affected with TMPO-related conditions. ClinVar contains an entry for this variant (Variation ID: 165468). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) indicates that this missense variant is not expected to disrupt TMPO protein function with a negative predictive value of 80%. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.29
BayesDel_addAF
Benign
-0.25
T
BayesDel_noAF
Benign
-0.54
CADD
Benign
14
DANN
Uncertain
0.98
DEOGEN2
Benign
0.17
T
Eigen
Benign
-0.25
Eigen_PC
Benign
-0.068
FATHMM_MKL
Uncertain
0.83
D
LIST_S2
Benign
0.38
T
M_CAP
Benign
0.0039
T
MetaRNN
Benign
0.085
T
MetaSVM
Benign
-1.1
T
MutationAssessor
Benign
0.97
L
PhyloP100
1.2
PrimateAI
Benign
0.35
T
PROVEAN
Benign
0.22
N
REVEL
Benign
0.022
Sift
Benign
0.081
T
Sift4G
Benign
0.21
T
Polyphen
0.035
B
Vest4
0.18
MutPred
0.26
Gain of catalytic residue at E299 (P = 0.0012);
MVP
0.23
MPC
0.074
ClinPred
0.079
T
GERP RS
3.6
Varity_R
0.12
gMVP
0.069
Mutation Taster
=96/4
polymorphism

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.020
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: rs369208265; hg19: chr12-98926944; API