chrM-9176-T-G
Variant summary
Our verdict is Likely pathogenic. Variant got 9 ACMG points: 9P and 0B. PS3_ModeratePS4_SupportingPM2_SupportingPP3PM5PP1_Moderate
This summary comes from the ClinGen Evidence Repository: The m.9176T>G (p.L217R) variant in MT-ATP6 has been reported in 9 individuals with features of primary mitochondrial disease from 3 families. Affected individuals had variable ages of onset (first months of life to 3 years old, one case with onset in late teens). Features included Leigh syndrome, seizures, ataxia, muscle weakness, dystonia, developmental regression with illness, axonal neuropathy, optic atrophy, and retinal dystrophy. Some individuals had gradual progression including one with onset in childhood but surviving to at least 40s. Others have progressed to death within months. Brain imaging in some individuals was consistent with Leigh syndrome and others with diffuse brain atrophy. Elevated blood and CSF lactate were noted. Heteroplasmy levels were >95% in multiple tissues for those with onset in childhood, 70% for gradually-progressive phenotype, and healthy family members had 28-50% heteroplasmy (PS4_supporting; PMIDs: 11245730, 11731285; Khailany et al., 2020 with no PMID). There are no reports of de novo occurrence of this variant. This variant segregated with disease in multiple affected members in multiple families and several healthy family members had lower to undetectable levels of the variant (PP1_moderate; PMIDs: 11245730, 11731285; Khailany et al., 2020 with no PMID). This variant is absent in population databases after removing sequences from individuals with mitochondrial disease (one occurrence in GenBank sequences is from individual with mitochondrial disease; absent in gnomAD v3.1.2 and Helix databset; PM2_supporting). This variant is located at the same amino acid position as another well-known pathogenic variant, m.9176T>C (p.L217P) (PM5). Several studies in E. coli (PMID:11119722), yeast (PMID:19454486), and cybrids (PMID:19160410) support the functional impact of this variant and independent studies showed independent deleterious effects of the variant (PS3_moderate). The computational predictor APOGEE gives a consensus rating of pathogenic with a score of 0.9 (Min=0, Max=1), which predicts a damaging effect on gene function (PP3). In summary, this variant meets criteria to be classified as likely pathogenic for primary mitochondrial disease inherited in a mitochondrial manner. This classification was approved by the NICHD/NINDS U24 Mitochondrial Disease Variant Curation Expert Panel on February 28, 2022. Mitochondrial DNA-specific ACMG/AMP criteria applied: PS3_moderate, PS4_supporting, PP1_moderate, PM2_supporting, PM5, PP3. LINK:https://erepo.genome.network/evrepo/ui/classification/CA340929/MONDO:0044970/014
Frequency
Consequence
ENST00000361899.2 missense
Scores
Clinical Significance
Conservation
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ACMG classification
Verdict is Likely_pathogenic. Variant got 9 ACMG points.
Transcripts
RefSeq
Gene | Transcript | HGVSc | HGVSp | Effect | #exon/exons | MANE | UniProt |
---|---|---|---|---|---|---|---|
ATP6 | ATP6.1 use as main transcript | c.650T>G | p.Leu217Arg | missense_variant | 1/1 | ||
COX3 | COX3.1 use as main transcript | upstream_gene_variant |
Ensembl
Gene | Transcript | HGVSc | HGVSp | Effect | #exon/exons | TSL | MANE | Appris | UniProt |
---|---|---|---|---|---|---|---|---|---|
MT-ATP6 | ENST00000361899.2 | c.650T>G | p.Leu217Arg | missense_variant | 1/1 | P1 | |||
MT-CO3 | ENST00000362079.2 | upstream_gene_variant | P1 |
Frequencies
GnomAD4 exome Cov.: 0
Mitomap
ClinVar
Submissions by phenotype
Leigh syndrome Pathogenic:1Other:1
not provided, no classification provided | literature only | GeneReviews | - | - - |
Pathogenic, criteria provided, single submitter | clinical testing | Wong Mito Lab, Molecular and Human Genetics, Baylor College of Medicine | Oct 17, 2019 | The NC_012920.1:m.9176T>G (YP_003024031.1:p.Leu217Arg) variant in MTATP6 gene is interpretated to be a Pathogenic variant based on the modified ACMG guidelines (unpublished). This variant meets the following evidence codes: PS1, PM9, PM10, PP3, PP4, PP7 - |
Mitochondrial complex 5 (ATP synthase) deficiency, mitochondrial type 1 Pathogenic:1
Pathogenic, no assertion criteria provided | literature only | OMIM | Aug 01, 2009 | - - |
Mitochondrial disease Pathogenic:1
Likely pathogenic, reviewed by expert panel | curation | ClinGen Mitochondrial Disease Nuclear and Mitochondrial Variant Curation Expert Panel, ClinGen | Mar 24, 2022 | The m.9176T>G (p.L217R) variant in MT-ATP6 has been reported in 9 individuals with features of primary mitochondrial disease from 3 families. Affected individuals had variable ages of onset (first months of life to 3 years old, one case with onset in late teens). Features included Leigh syndrome, seizures, ataxia, muscle weakness, dystonia, developmental regression with illness, axonal neuropathy, optic atrophy, and retinal dystrophy. Some individuals had gradual progression including one with onset in childhood but surviving to at least 40s. Others have progressed to death within months. Brain imaging in some individuals was consistent with Leigh syndrome and others with diffuse brain atrophy. Elevated blood and CSF lactate were noted. Heteroplasmy levels were >95% in multiple tissues for those with onset in childhood, 70% for gradually-progressive phenotype, and healthy family members had 28-50% heteroplasmy (PS4_supporting; PMIDs: 11245730, 11731285; Khailany et al., 2020 with no PMID). There are no reports of de novo occurrence of this variant. This variant segregated with disease in multiple affected members in multiple families and several healthy family members had lower to undetectable levels of the variant (PP1_moderate; PMIDs: 11245730, 11731285; Khailany et al., 2020 with no PMID). This variant is absent in population databases after removing sequences from individuals with mitochondrial disease (one occurrence in GenBank sequences is from individual with mitochondrial disease; absent in gnomAD v3.1.2 and Helix databset; PM2_supporting). This variant is located at the same amino acid position as another well-known pathogenic variant, m.9176T>C (p.L217P) (PM5). Several studies in E. coli (PMID: 11119722), yeast (PMID: 19454486), and cybrids (PMID: 19160410) support the functional impact of this variant and independent studies showed independent deleterious effects of the variant (PS3_moderate). The computational predictor APOGEE gives a consensus rating of pathogenic with a score of 0.9 (Min=0, Max=1), which predicts a damaging effect on gene function (PP3). In summary, this variant meets criteria to be classified as likely pathogenic for primary mitochondrial disease inherited in a mitochondrial manner. This classification was approved by the NICHD/NINDS U24 Mitochondrial Disease Variant Curation Expert Panel on February 28, 2022. Mitochondrial DNA-specific ACMG/AMP criteria applied: PS3_moderate, PS4_supporting, PP1_moderate, PM2_supporting, PM5, PP3. - |
not provided Pathogenic:1
Pathogenic, criteria provided, single submitter | clinical testing | Institute of Medical Genetics and Applied Genomics, University Hospital Tübingen | Jun 17, 2021 | - - |
Leber optic atrophy Pathogenic:1
Likely pathogenic, no assertion criteria provided | clinical testing | Genomics England Pilot Project, Genomics England | - | - - |
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at