rs199474820

Variant names:

• chrM-7510-T-C
• rs199474820
• unassigned_transcript_4800:c.5A>G

Variant summary

Our verdict is Pathogenic. Variant got 10 ACMG points: 10P and 0B. PM2 PP5_Very_Strong

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

• Frequency: Mitomap GenBank: Absent
• Consequence: TRNS1 missense
• Scores: Mitotip Uncertain 15
• Clinical Significance: Likely pathogenic reviewed by expert panel P:2 O:1 SNHL
• Conservation: PhyloP100: 1.24

Genes affected

TRNS1 (HGNC:7497): (mitochondrially encoded tRNA serine 1 (UCN))

COX2 (HGNC:7421): (mitochondrially encoded cytochrome c oxidase II) Contributes to cytochrome-c oxidase activity. Predicted to be involved in mitochondrial electron transport, cytochrome c to oxygen and positive regulation of vasoconstriction. Located in mitochondrial inner membrane. Part of respiratory chain complex IV. Biomarker of Huntington's disease and stomach cancer. [provided by Alliance of Genome Resources, Apr 2022]

TRND (HGNC:7478): (mitochondrially encoded tRNA aspartic acid)

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]

ACMG classification

Verdict is Pathogenic. Variant got 10 ACMG points.

• PM2: No frequency data in Mitomap. Probably very rare.
• PP5: Variant M-7510-T-C is Pathogenic according to our data. Variant chrM-7510-T-C is described in ClinVar as [Likely_pathogenic]. Clinvar id is 9565.Status of the report is reviewed_by_expert_panel, 3 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TRNS1	unassigned_transcript_4800	c.5A>G	p.Lys2Arg	missense_variant	Exon 1 of 1
COX2	unassigned_transcript_4802	c.-76T>C		upstream_gene_variant
TRND	unassigned_transcript_4801	c.-8T>C		upstream_gene_variant
COX1	unassigned_transcript_4799	c.*65T>C		downstream_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.

Mitomap

SNHL

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:2 Other:1

Revision: reviewed by expert panel

Submissions by phenotype

Mitochondrial non-syndromic sensorineural hearing loss Pathogenic:1 Other:1

-

GeneReviews

Significance: not provided

Review Status: no classification provided

Collection Method: literature only

- -

Sep 01, 2000

OMIM

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: literature only

- -

Mitochondrial disease Pathogenic:1

Mar 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.7510T>C variant in MT-TS1 has been reported in at least nine individuals across six different families with primary mitochondrial disease (PS4_moderate; PMIDs: 29299381, 18028453, 23430555, 15292920, 10978361, 12471220). The most common feature in affected individuals was sensorineural hearing loss. Age of onset ranged from 2-70 years old, and heteroplasmy levels in affected individuals ranged from 90% to >99%. Of note, some unaffected family members had the variant present at homoplasmy, as well (PMID: 12471220). Additional clinical features were seen in at least two families. One family reported in the medical literature also had migraines, ataxia, short stature, epilepsy, cognitive impairment, tremor, and restless leg syndrome (PMID: 29299381). The second family was known to some members of this expert panel, and the expert panel agreed to include this case. This variant segregated with disease manifestations in two families with hearing loss as all affected individuals had the variant present at heteroplasmy levels ranging from 90% to >99% (PP1_moderate; PMIDs: 29299381, 10978361). There are no de novo occurrences of this variant to our knowledge. The computational predictor MitoTIP suggests this variant is pathogenic (68.6 percentile) and HmtVAR predicts it to be pathogenic score of 0.6 (PP3). There is one occurrence in the GenBank population database, and the variant is absent in the Helix dataset and gnomAD v.3.1.2. Although there is one occurrence, the frequency is still low (PM2_supporting). There are no cybrids, single fiber studies, or other functional assays reported on this variant. 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 March 13, 2023. Mitochondrial DNA-specific ACMG/AMP criteria applied (PMID: 32906214): PS4_moderate, PP1_moderate, PM2_supporting, PP3. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
Mitotip	Uncertain	15
Hmtvar	Pathogenic	0.60

Splicing

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

Publications

LitVar

Other links and lift over

dbSNP: rs199474820; hg19: chrM-7511;