chrM-12239-C-T

Position:

• chrM-12239-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.12239C>T variant in MT-TS2 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 3.631% of individuals in the GenBank dataset (BA1), including in haplogroup B4a (90.9% of individuals). Furthermore, this variant is seen in the gnomAD dataset (v3.1.2) at an overall homoplasmic allele frequency of 0.2% including in haplogroup B at 7%. 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 5th percentile, as does HmtVar with a score of <0.35 (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/CA10581287/MONDO:0044970/014

• Frequency: Mitomap GenBank: 𝑓 0.033 (AC: 2042)
• Consequence: MT-TS2 ENST00000387449.1 non_coding_transcript_exon
• Scores: Mitotip Benign 2.8
• Clinical Significance: Benign reviewed by expert panel B:3 No linked disesase in Mitomap
• Conservation: PhyloP100: -9.03

Genes affected

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

TRNS2 (HGNC:):

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

MT-TH (HGNC:7487): (mitochondrially encoded tRNA histidine)

ACMG classification

Verdict is Benign. Variant got -9 ACMG points.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
TRNS2	TRNS2.1	n.33C>T		non_coding_transcript_exon_variant	1/1
TRNL2	TRNL2.1			upstream_gene_variant
TRNH	TRNH.1			downstream_gene_variant

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
MT-TS2	ENST00000387449.1	n.33C>T		non_coding_transcript_exon_variant	1/1
MT-TL2	ENST00000387456.1			upstream_gene_variant
MT-TH	ENST00000387441.1			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 GenBank AF: 0.033 AC: 2042

Gnomad homoplasmic AF: 0.0022 AC: 123 AN: 56434

Gnomad heteroplasmic AF: 0.000018 AC: 1 AN: 56434

Mitomap

No disease associated.

ClinVar

Significance: Benign

Submissions summary: Benign:3

Revision: reviewed by expert panel

Submissions by phenotype

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.12239C>T variant in MT-TS2 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 3.631% of individuals in the GenBank dataset (BA1), including in haplogroup B4a (90.9% of individuals). Furthermore, this variant is seen in the gnomAD dataset (v3.1.2) at an overall homoplasmic allele frequency of 0.2% including in haplogroup B at 7%. 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 5th percentile, as does HmtVar with a score of <0.35 (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. -

not provided Benign:1

Benign, criteria provided, single submitter

clinical testing

Center for Pediatric Genomic Medicine, Children's Mercy Hospital and Clinics

Jun 02, 2015

- -

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.12239C>T variant in MT-TS2 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	2.8
Hmtvar	Benign	0.0

Splicing

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

Publications

LitVar

Other links and lift over

dbSNP: rs376062400; hg19: chrM-12240;