rs199476132

Variant summary

Our verdict is Pathogenic. Variant got 10 ACMG points: 10P and 0B. PM2PP5_Very_Strong

Variant has been reported in ClinVar as Likely pathogenic (★★★).

Frequency

Mitomap GenBank:
Absent

Consequence

TRNN
stop_lost

Scores

Mitotip
Uncertain
16

Clinical Significance

Likely pathogenic reviewed by expert panel P:5
Multiorgan-failure-/-myopathy

Conservation

PhyloP100: 1.98
Variant links:
Genes affected
TRNN (HGNC:7493): (mitochondrially encoded tRNA asparagine)
COX1 (HGNC:7419): (mitochondrially encoded cytochrome c oxidase I) Contributes to cytochrome-c oxidase activity. Predicted to be involved in electron transport coupled proton transport and mitochondrial electron transport, cytochrome c to oxygen. Part of mitochondrial respiratory chain complex III and mitochondrial respiratory chain complex IV. [provided by Alliance of Genome Resources, Apr 2022]
TRNA (HGNC:7475): (mitochondrially encoded tRNA alanine)
ND2 (HGNC:7456): (mitochondrially encoded NADH dehydrogenase 2) Enables NADH dehydrogenase (ubiquinone) activity. Involved in mitochondrial electron transport, NADH to ubiquinone and mitochondrial respiratory chain complex I assembly. Part of mitochondrial respiratory chain complex I. Implicated in Leber hereditary optic neuropathy; multiple sclerosis; myocardial infarction; neurodegenerative disease (multiple); and urinary bladder cancer. [provided by Alliance of Genome Resources, Apr 2022]
TRNW (HGNC:7501): (mitochondrially encoded tRNA tryptophan)
TRNC (HGNC:7477): (mitochondrially encoded tRNA cysteine)
TRNY (HGNC:7502): (mitochondrially encoded tRNA tyrosine)

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ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 10 ACMG points.

PM2
No frequency data in Mitomap. Probably very rare.
PP5
Variant M-5728-T-C is Pathogenic according to our data. Variant chrM-5728-T-C is described in ClinVar as [Likely_pathogenic]. Clinvar id is 9622.Status of the report is reviewed_by_expert_panel, 3 stars.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
TRNNunassigned_transcript_4796 c.2A>G p.Ter1Trpext*? stop_lost Exon 1 of 1
COX1unassigned_transcript_4799 c.-176T>C upstream_gene_variant
TRNAunassigned_transcript_4795 c.-73A>G upstream_gene_variant

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt

Frequencies

GnomAD4 exome
Cov.:
0
We have no GnomAD4 genomes data on this position. Probably position not covered by the project.
Gnomad homoplasmic
AF:
0.0
AC:
0
AN:
56428
Gnomad heteroplasmic
AF:
0.000018
AC:
1
AN:
56428

Mitomap

Multiorgan-failure-/-myopathy

ClinVar

Significance: Likely pathogenic
Submissions summary: Pathogenic:5
Revision: reviewed by expert panel
LINK: link

Submissions by phenotype

Mitochondrial complex IV deficiency, nuclear type 1 Pathogenic:2
Aug 01, 2006
OMIM
Significance: Pathogenic
Review Status: no assertion criteria provided
Collection Method: literature only

- -

May 04, 2022
Mendelics
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Mitochondrial disease Pathogenic:1
Feb 13, 2023
ClinGen Mitochondrial Disease Nuclear and Mitochondrial Variant Curation Expert Panel, ClinGen
Significance: Likely pathogenic
Review Status: reviewed by expert panel
Collection Method: curation

The m.5728T>C variant in MT-TN has been reported in three unrelated individuals with primary mitochondrial disease (PS4_supporting). Onset was in infancy or childhood, and features seen in these individuals included myopathy, ataxia, developmental delay, multiorgan failure, ptosis, and ophthalmoplegia. The variant was seen at varying heteroplasmy levels in affected individuals, including undetectable to 50% in blood and 41-97% in muscle (PMIDs: 16908752, 23847141, 31026515). The variant was confirmed to have occurred de novo in one of the reported cases, as the variant was undetectable in the mother’s blood and muscle by next-generation sequencing (PMID: 31026515, PM6). In another case, the variant appeared to have arisen de novo as it was not detected in blood from the healthy mother, two siblings, and maternal grandmother, however technology used at the time would not have detected low levels of the variant and additional tissues were not assessed (PMID: 16908752). No details of family member testing were provided in the third case. There are no other large families reported in the medical literature with this variant to consider for evidence of segregation. There is one occurrence of this variant in GenBank dataset and it is absent in gnomAD v3.1.2 and in the Helix dataset, therefore the overall frequency is still very low (PM2_supporting). The computational predictor MitoTIP suggests this variant is pathogenic, scoring in the 71st percentile and HmtVAR also predicts it to be pathogenic, scoring 0.75 (PP3). Cybrid studies support the functional impact of this variant as a combined defect of complexes I and IV was seen (PS3_supporting; PMID: 6908752). 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 ClinGen Mitochondrial Disease Variant Curation Expert Panel on February 13, 2023. Mitochondrial DNA-specific ACMG/AMP criteria applied (PMID: 32906214): PS4_supporting, PS3_supporting, PM2_supporting, PP3, PM6. -

MITOCHONDRIAL COMPLEX I DEFICIENCY, MITOCHONDRIAL TYPE 2 Pathogenic:1
Aug 01, 2006
OMIM
Significance: Pathogenic
Review Status: no assertion criteria provided
Collection Method: literature only

- -

MELAS syndrome Pathogenic:1
Jul 12, 2019
Wong Mito Lab, Molecular and Human Genetics, Baylor College of Medicine
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

The NC_012920.1:m.5728T>C variant in MT-TN 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, PM8, PM9, PP3, PP6 -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
Mitotip
Uncertain
16
Hmtvar
Pathogenic
0.75

Splicing

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Below is the list of publications found by LitVar. It may be empty.

Other links and lift over

dbSNP: rs199476132; hg19: chrM-5729; API