rs199476137

Variant names:

• chrM-9203-CAT-C
• rs199476137
• unassigned_transcript_4805:c.679_680delTA

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: 𝑓 0.0 (AC: 0)
• Consequence: ATP6 frameshift, stop_lost, splice_region
• Clinical Significance: Likely pathogenic reviewed by expert panel P:3 Encephalopathy-/-Seizures-/-Lacticacidemia
• Conservation: PhyloP100: 4.88

Genes affected

ATP6 (HGNC:7414): (mitochondrially encoded ATP synthase 6) Contributes to proton-transporting ATP synthase activity, rotational mechanism. Involved in mitochondrial ATP synthesis coupled proton transport. Part of mitochondrial proton-transporting ATP synthase complex. Implicated in Leber hereditary optic neuropathy; NARP syndrome; Parkinson's disease; multiple sclerosis; and systemic lupus erythematosus. [provided by Alliance of Genome Resources, Apr 2022]

COX3 (HGNC:7422): (mitochondrially encoded cytochrome c oxidase III) Predicted to enable electron transfer activity and oxidoreduction-driven active transmembrane transporter activity. Involved in respiratory chain complex IV assembly. Part of respiratory chain complex IV. Implicated in MELAS syndrome. [provided by Alliance of Genome Resources, Apr 2022]

ACMG classification

Verdict is Pathogenic. Variant got 10 ACMG points.

• PM2: Very low frequency in mitomap database: 0.0
• PP5: Variant M-9203-CAT-C is Pathogenic according to our data. Variant chrM-9203-CAT-C is described in ClinVar as [Likely_pathogenic]. Clinvar id is 9646.Status of the report is reviewed_by_expert_panel, 3 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
ATP6	unassigned_transcript_4805	c.679_680delTA	p.Ter227fs	frameshift_variant, stop_lost, splice_region_variant	Exon 1 of 1
COX3	unassigned_transcript_4806	c.-3_-2delAT		upstream_gene_variant

Ensembl

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

Frequencies

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

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

Mitomap GenBank AF: 0.0 AC: 0

Mitomap

Encephalopathy-/-Seizures-/-Lacticacidemia

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:3

Revision: reviewed by expert panel

Submissions by phenotype

Mitochondrial disease Pathogenic:1

Jun 30, 2022

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.9205_9206delTA (p.Ter227M) variant in MT-ATP6 has been reported in two unrelated probands with features of primary mitochondrial disease (neonatal lactic acidosis, failure to thrive, spasticity, microcephaly, developmental delay; PS4_supporting; PMIDs: 8739943, 15265003). The variant was de novo in one of these individuals (absent in mother and maternal grandmother's lymphocytes via PCR-SSCP; PM6_supporting; PMID: 8739943). In the other family, this variant segregated with disease in two unaffected family members as they had lower levels of the variant, however the unaffected mother’s heteroplasmy level was still fairly high at >90% (PMID: 15265003). This variant is absent in the GenBank dataset, Helix dataset, and gnomAD v3.1.2 (PM2_supporting). There are no cybrids or single fiber studies reported on this variant. The loss residue removes the termination codon for MT-ATP6 and sets MT-CO3 immediately in frame. This results in decreased steady state level of RNA14, the ATPase 8- and 6-encoding bi-cistronic mRNA unit, causing dysregulation of mRNA stability (PM4, PMID: 12915481). This variant meets criteria to be classified as uncertain significance however, after extensive discussion, this Expert Panel elected to modify the classification to likely pathogenic given the functional evidence showing destabilization of the RNA. In summary, this variant is classified as likely pathogenic for primary mitochondrial disease inherited in a mitochondrial manner. Mitochondrial DNA-specific ACMG/AMP criteria applied (PMID: 32906214): PM6_supporting, PM2_supporting, PM4, PS4_supporting. -

Seizures and lactic acidosis Pathogenic:1

Sep 15, 2003

OMIM

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: literature only

- -

Leber optic atrophy Pathogenic:1

May 04, 2022

Mendelics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Splicing

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

Publications

LitVar

Other links and lift over

dbSNP: rs199476137; hg19: chrM-9204;