ClinVar Miner

Submissions for variant NC_012920.1(MT-CYB):m.1644G>A

dbSNP: rs587776441
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Total submissions: 4
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Submitter RCV SCV Clinical significance Condition Last evaluated Review status Method Comment
ClinGen Mitochondrial Disease Nuclear and Mitochondrial Variant Curation Expert Panel, ClinGen RCV001796793 SCV002037595 likely pathogenic Mitochondrial disease 2021-12-10 reviewed by expert panel curation The m.1644G>A variant in MT-TV was reviewed by the Mitochondrial Disease Nuclear and Mitochondrial Variant Curation Expert Panel as part of the variant pilot for mitochondrial DNA variant specifications (McCormick et al., 2020; PMID: 32906214). This variant has been reported in 7 individuals with primary mitochondrial disease with variable features including cardiac (hypertrophic cardiomyopathy, LBBB); neurologic (neurodegeneration/dementia, stroke-like episodes, recurrent encephalopathy, epilepsy, ataxia, dystonia, Parkinsonism, mood disorder/disturbances, fatigue, muscle weakness, exercise intolerance, neuropathy, cognitive impairment, developmental regression); audiologic (bilateral sensorineural hearing loss); renal (cystic renal disease); GI (severe GI dysmotility, cachexia); and endocrine (diabetes) concerns as well as lab abnormalities (elevated blood and CSF lactate, elevated CK), and brain imaging abnormalities (atrophy, basal ganglia lesions, MRS lactate peak); with heteroplasmy levels in multiple tissues ranging from 85% to homoplasmy (PS4; PMIDs: 15320572, 23847141, 18314141, 21986556, 24691472). This variant heteroplasmy level segregated with severity in 2 family members from 1 family (PP1; PMID: 15320572). This variant is located at the same position as another variant associated with mitochondrial disease, m.1644G>T (PM5_supporting). This variant is absent in the GenBank data set and gnomAD v3.1.2 (PM2_supporting). The computational predictor MitoTIP suggests this variant impacts the function of this tRNA, as does HmtVar with a score of 1 (PP3). Cybrid studies supported the functional impact of this variant (PS3_supporting; PMID: 24691472). 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 U24 ClinGen Mitochondrial Disease Variant Curation Expert Panel as of August 20, 2020. Mitochondrial DNA-specific ACMG/AMP criteria applied: PS4, PS3_supporting, PM2_supporting, PM5_supporting, PP1, PP3.
Wong Mito Lab, Molecular and Human Genetics, Baylor College of Medicine RCV000850677 SCV000992908 pathogenic Juvenile myopathy, encephalopathy, lactic acidosis AND stroke 2019-07-12 criteria provided, single submitter clinical testing The NC_012920.1:m.1644G>A variant in MT-TV gene is interpreted to be a Pathogenic variant based on the modified ACMG guidelines (unpublished). This variant meets the following evidence codes reported in the guidelines: PS3, PS5, PP3
Mendelics RCV000850677 SCV002517736 pathogenic Juvenile myopathy, encephalopathy, lactic acidosis AND stroke 2022-05-04 criteria provided, single submitter clinical testing
GeneReviews RCV000850677 SCV004042649 not provided Juvenile myopathy, encephalopathy, lactic acidosis AND stroke no assertion provided literature only

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