chrM-12293-G-A

Position:

• chrM-12293-G-A

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 2P and 0B. PM2

The ENST00000387456.1(MT-TL2):​n.28G>A variant causes a non coding transcript exon change involving the alteration of a conserved nucleotide. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Mitomap GenBank: Absent
• Consequence: MT-TL2 ENST00000387456.1 non_coding_transcript_exon
• Scores: Mitotip Uncertain 15
• Clinical Significance: Uncertain significance criteria provided, single submitter P:1 U:1 Axial-mitochondrial-myopathy-/-EXIT+myalgia+ptosis
• Conservation: PhyloP100: 7.50

Genes affected

MT-TL2 (HGNC:7491): (mitochondrially encoded tRNA leucine 2 (CUN))

TRNL2 (HGNC:):

MT-ND5 (HGNC:7461): (mitochondrially encoded NADH dehydrogenase 5) 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; Leigh disease; and MELAS syndrome. [provided by Alliance of Genome Resources, Apr 2022]

MT-TS2 (HGNC:7498): (mitochondrially encoded tRNA serine 2 (AGU/C))

ACMG classification

Verdict is Uncertain_significance. Variant got 2 ACMG points.

• PM2: No frequency data in Mitomap. Probably very rare.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
TRNL2	TRNL2.1	n.28G>A		non_coding_transcript_exon_variant	1/1
TRNS2	TRNS2.1			downstream_gene_variant

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
MT-TL2	ENST00000387456.1	n.28G>A		non_coding_transcript_exon_variant	1/1
MT-ND5	ENST00000361567.2			upstream_gene_variant				P1
MT-TS2	ENST00000387449.1			downstream_gene_variant

Frequencies

GnomAD4 exome Cov.: 0

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

Mitomap

Axial-mitochondrial-myopathy-/-EXIT+myalgia+ptosis

ClinVar

Significance: Uncertain significance

Submissions summary: Pathogenic:1 Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Mitochondrial disease Pathogenic:1

Pathogenic, no assertion criteria provided

in vitro

Medical Genetics, CHU Nice

Oct 01, 2019

The patient had exercise intolerance, myalgia, and unilateral ptosis. -

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

Uncertain significance, 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.12293G>A variant in MT-TL2 gene is interpreted to be a Unknown Significance variant based on the modified ACMG guidelines (unpublished). This variant meets the following evidence codes reported in the guidelines: PP3, PP6, BP5 -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
Mitotip	Uncertain	15
Hmtvar	Benign	0.050

Splicing

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

Publications

LitVar

Other links and lift over

dbSNP: rs1603223654; hg19: chrM-12294;