M-7476-C-T

Position:

• chrM-7476-C-T

Variant summary

Our verdict is Benign. Variant got -9 ACMG points: 0P and 9B. BP4 BA1

This summary comes from the ClinGen Evidence Repository: The m.7476C>T variant in MT-TS1 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 is seen in 1.310% of individuals in the GenBank dataset (BA1), including in haplogroups J2a (99.7% of individuals) and J2b (98.85% of individuals). Furthermore, this variant is seen in the gnomAD dataset (v3.1.2) at an overall homoplasmic allele frequency of 1% including in haplogroup J at 20%. If an affected individual is not a member this haplogroup, further evaluation of the variant in that particular individual should be considered. The computational predictor MitoTIP suggests this variant does not impact the function of this tRNA with a score in the 20th percentile, as does HmtVar with a score of 0.1 (BP4). In summary, this variant meets criteria to be classified as benign. This classification was approved by the NICHD U24 Mitochondrial Disease Variant Curation Expert Panel as of August 20, 2020. Mitochondrial DNA-specific ACMG/AMP criteria applied: BA1, BP4. LINK:https://erepo.genome.network/evrepo/ui/classification/CA131013/MONDO:0044970/014

• Frequency: Mitomap GenBank: 𝑓 0.013 (AC: 805)
• Consequence: MT-TS1 ENST00000387416.2 non_coding_transcript_exon
• Scores: Mitotip Benign 0.016
• Clinical Significance: Benign reviewed by expert panel B:3 No linked disesase in Mitomap
• Conservation: PhyloP100: -0.836

Genes affected

MT-TS1 (HGNC:7497): (mitochondrially encoded tRNA serine 1 (UCN))

TRNS1 (HGNC:):

MT-CO1 (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]

MT-TD (HGNC:7478): (mitochondrially encoded tRNA aspartic acid)

ACMG classification

Verdict is Benign. Variant got -9 ACMG points.

• BP4: For more information check the summary or visit ClinGen Evidence Repository.
• BA1: For more information check the summary or visit ClinGen Evidence Repository.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
TRNS1	TRNS1.1	n.39G>A		non_coding_transcript_exon_variant	1/1
COX1	COX1.1			downstream_gene_variant			YP_003024028.1
TRND	TRND.1			upstream_gene_variant

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
MT-TS1	ENST00000387416.2	n.39G>A		non_coding_transcript_exon_variant	1/1
MT-CO1	ENST00000361624.2			downstream_gene_variant				ENSP00000354499	P1
MT-TD	ENST00000387419.1			upstream_gene_variant

Frequencies

GnomAD4 exome Cov.: 0

We have no GnomAD4 genomes data on this position. Probably position not covered by the project.

Mitomap GenBank AF: 0.013 AC: 805

Gnomad homoplasmic AF: 0.011 AC: 622 AN: 56432

Gnomad heteroplasmic AF: 0.0 AC: 0 AN: 56432

Alfa AF: 0.0156 Hom.: 609

Mitomap

No disease associated.

ClinVar

Significance: Benign

Submissions summary: Benign:3

Revision: reviewed by expert panel

Submissions by phenotype

not specified Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Oct 16, 2013

m.7476C>T in MT-TS1: This variant is not expected to have clinical significance because it has been observed at equal frequencies in Caucasian individuals with hearing loss and in the general population (Houshmand 1994, Thomas 1996, Sternbe rg 1998, Li 2004, Konings 2008, mtDB-Human Mitochondrial Genome Database). -

Mitochondrial disease Benign:1

Benign, reviewed by expert panel

curation

ClinGen Mitochondrial Disease Nuclear and Mitochondrial Variant Curation Expert Panel, ClinGen

Jan 10, 2022

The m.7476C>T variant in MT-TS1 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 is seen in 1.310% of individuals in the GenBank dataset (BA1), including in haplogroups J2a (99.7% of individuals) and J2b (98.85% of individuals). Furthermore, this variant is seen in the gnomAD dataset (v3.1.2) at an overall homoplasmic allele frequency of 1% including in haplogroup J at 20%. If an affected individual is not a member this haplogroup, further evaluation of the variant in that particular individual should be considered. The computational predictor MitoTIP suggests this variant does not impact the function of this tRNA with a score in the 20th percentile, as does HmtVar with a score of 0.1 (BP4). In summary, this variant meets criteria to be classified as benign. This classification was approved by the NICHD U24 Mitochondrial Disease Variant Curation Expert Panel as of August 20, 2020. Mitochondrial DNA-specific ACMG/AMP criteria applied: BA1, BP4. -

Juvenile myopathy, encephalopathy, lactic acidosis AND stroke Benign:1

Benign, criteria provided, single submitter

clinical testing

Wong Mito Lab, Molecular and Human Genetics, Baylor College of Medicine

Jul 12, 2019

The NC_012920.1:m.7476C>T variant in MT-TS1 gene is interpreted to be a Benign variant based on the modified ACMG guidelines (unpublished). This variant meets the following evidence codes reported in the guidelines: BS1, BS2, BP4 -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
Mitotip	Benign	0.016
Hmtvar	Benign	0.10

Splicing

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

Publications

LitVar

Other links and lift over

dbSNP: rs201950015; hg19: chrM-7477;