Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1PM2PP5_Very_Strong
The NM_012123.4(MTO1):c.1324C>T(p.Arg442*) variant causes a stop gained change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000409 in 1,613,942 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 Likely pathogenic (★★). Variant results in nonsense mediated mRNA decay.
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]
Verdict is Pathogenic. Variant got 18 ACMG points.
PVS1
Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
PM2
Very rare variant in population databases, with high coverage;
PP5
Variant 6-73482103-C-T is Pathogenic according to our data. Variant chr6-73482103-C-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 445467.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
Mitochondrial hypertrophic cardiomyopathy with lactic acidosis due to MTO1 deficiency Pathogenic:1
Pathogenic, criteria provided, single submitter
clinical testing
Labcorp Genetics (formerly Invitae), Labcorp
Aug 04, 2023
This sequence change creates a premature translational stop signal (p.Arg442*) in the MTO1 gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in MTO1 are known to be pathogenic (PMID: 22608499, 25058219). This variant is present in population databases (rs200583827, gnomAD 0.05%). This variant has not been reported in the literature in individuals affected with MTO1-related conditions. ClinVar contains an entry for this variant (Variation ID: 445467). For these reasons, this variant has been classified as Pathogenic. -
not provided Pathogenic:1
Likely pathogenic, criteria provided, single submitter
clinical testing
Center for Pediatric Genomic Medicine, Children's Mercy Hospital and Clinics