Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM2PP3PP5
The NM_012123.4(MTO1):c.1933C>A(p.Arg645Ser) variant causes a missense change. The variant allele was found at a frequency of 0.0000304 in 1,612,552 control chromosomes in the GnomAD database, including 1 homozygotes. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).
MTO1 (HGNC:19261): (mitochondrial tRNA translation optimization 1) This gene encodes a mitochondrial protein thought to be involved in mitochondrial tRNA modification. The encoded protein may also play a role in the expression of the non-syndromic and aminoglycoside-induced deafness phenotypes associated with a specific mutation in the mitochondrial 12S rRNA gene. Multiple transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Jul 2008]
EEF1A1 (HGNC:3189): (eukaryotic translation elongation factor 1 alpha 1) This gene encodes an isoform of the alpha subunit of the elongation factor-1 complex, which is responsible for the enzymatic delivery of aminoacyl tRNAs to the ribosome. This isoform (alpha 1) is expressed in brain, placenta, lung, liver, kidney, and pancreas, and the other isoform (alpha 2) is expressed in brain, heart and skeletal muscle. This isoform is identified as an autoantigen in 66% of patients with Felty syndrome. This gene has been found to have multiple copies on many chromosomes, some of which, if not all, represent different pseudogenes. [provided by RefSeq, Jul 2008]
Verdict is Uncertain_significance. Variant got 4 ACMG points.
PM2
Very rare variant in population databases, with high coverage;
PP3
MetaRNN computational evidence supports a deleterious effect, 0.835
PP5
Variant 6-73500589-C-A is Pathogenic according to our data. Variant chr6-73500589-C-A is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 402215.We mark this variant Likely_pathogenic, oryginal submissions are: {Likely_pathogenic=1, Uncertain_significance=2}. Variant chr6-73500589-C-A is described in Lovd as [Pathogenic].
Lupski Lab, Baylor-Hopkins CMG, Baylor College of Medicine
Significance: Likely pathogenic
Review Status: criteria provided, single submitter
Collection Method: research
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Mitochondrial hypertrophic cardiomyopathy with lactic acidosis due to MTO1 deficiency Uncertain:1
Jun 13, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing
This sequence change replaces arginine, which is basic and polar, with serine, which is neutral and polar, at codon 645 of the MTO1 protein (p.Arg645Ser). This variant is present in population databases (rs746382157, gnomAD 0.02%). This missense change has been observed in individual(s) with congenital brain abnormalities (PMID: 26539891). This variant is also known as c.C2053A (p.R685S). ClinVar contains an entry for this variant (Variation ID: 402215). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) has been performed at Invitae for this missense variant, however the output from this modeling did not meet the statistical confidence thresholds required to predict the impact of this variant on MTO1 protein function. 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. -
not provided Uncertain:1
Aug 19, 2020
GeneDx
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing
This variant is associated with the following publications: (PMID: 31589614, 26539891) -