12-98533166-G-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
Consequence
ENST00000266732.8 missense
Scores
Clinical Significance
Conservation
Publications
- familial isolated dilated cardiomyopathyInheritance: AD Classification: SUPPORTIVE, NO_KNOWN Submitted by: ClinGen, Orphanet
- dilated cardiomyopathyInheritance: AD Classification: NO_KNOWN Submitted by: Ambry Genetics
- hypertrophic cardiomyopathyInheritance: AD Classification: NO_KNOWN Submitted by: ClinGen
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ACMG classification
Our verdict: Likely_benign. The variant received -6 ACMG points.
Transcripts
RefSeq
Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | MANE | Protein | UniProt |
---|---|---|---|---|---|---|---|---|
TMPO | NM_001032283.3 | c.565+1328G>T | intron_variant | Intron 3 of 8 | ENST00000556029.6 | NP_001027454.1 |
Ensembl
Frequencies
GnomAD3 genomes AF: 0.0000460 AC: 7AN: 152200Hom.: 0 Cov.: 33 show subpopulations
GnomAD2 exomes AF: 0.0000239 AC: 6AN: 251310 AF XY: 0.0000221 show subpopulations
GnomAD4 exome AF: 0.0000499 AC: 73AN: 1461818Hom.: 0 Cov.: 32 AF XY: 0.0000495 AC XY: 36AN XY: 727206 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.0000460 AC: 7AN: 152200Hom.: 0 Cov.: 33 AF XY: 0.0000269 AC XY: 2AN XY: 74364 show subpopulations
Age Distribution
ClinVar
Submissions by phenotype
not specified Uncertain:3
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. -
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. -
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not provided Uncertain:1
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
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:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at