rs28616230

Positions:

• chrM-4171-C-A
• chrM-4171-C-T

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PM2 PP5_Strong

In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★★).

• Frequency: Mitomap GenBank: Absent
• Consequence: ND1 missense
• Scores: Apogee2 Pathogenic 0.80
• Clinical Significance: Uncertain significance reviewed by expert panel P:3 U:1 O:1 LHON-/-Leigh-like-phenotype
• Conservation: PhyloP100: -0.734

Genes affected

ND1 (HGNC:):

ACMG classification

Verdict is Likely_pathogenic. Variant got 6 ACMG points.

• PM2: No frequency data in Mitomap. Probably very rare.
• PP5: Variant M-4171-C-A is Pathogenic according to our data. Variant chrM-4171-C-A is described in ClinVar as [Uncertain_significance]. Clinvar id is 9732.Status of the report is reviewed_by_expert_panel, 3 stars. We mark this variant Likely_pathogenic, oryginal submissions are: {Uncertain_significance=1, Pathogenic=1, not_provided=1, Likely_pathogenic=1}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
ND1	unassigned_transcript_4790	c.865C>A	p.Leu289Ile	missense_variant	1/1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	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

LHON-/-Leigh-like-phenotype

ClinVar

Significance: Uncertain significance

Submissions summary: Pathogenic:3 Uncertain:1 Other:1

Revision: reviewed by expert panel

Submissions by phenotype

Leber optic atrophy Pathogenic:3 Other:1

Likely pathogenic, criteria provided, single submitter	clinical testing	Wong Mito Lab, Molecular and Human Genetics, Baylor College of Medicine	Oct 17, 2019	The NC_012920.1:m.4171C>A (YP_003024026.1:p.Leu289Met) variant in MTND1 gene is interpretated to be a Likely Pathogenic variant based on the modified ACMG guidelines (unpublished). This variant meets the following evidence codes: PS1, PM9, PP4 -
not provided, no classification provided	literature only	GeneReviews	-	This mitochondrial DNA variant affects function. It hase been identified in at least two independent LHON pedigrees and segregates with affected disease status. -
Pathogenic, criteria provided, single submitter	clinical testing	Mendelics	May 04, 2022	- -
Pathogenic, no assertion criteria provided	literature only	OMIM	May 01, 2002	- -

Mitochondrial disease Uncertain:1

Uncertain significance, reviewed by expert panel

curation

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

Jun 30, 2022

The m.4171C>A (p.L289M) variant in MT-ND1 has been reported in 13 individuals with primary mitochondrial disease with features falling under the LHON and/or Leigh syndrome spectrums with variable brain lesions (PS4_moderate, PMIDs: 12112111, 19555656, 20491810, 22879922, 24884847, 32652755, 34670133, 35104579, 32045392; Cui et al., 2006 with no PMID; of note, the two families in PMID: 12112111 might be in the same haplogroup although there is no known kinship). Additionally, this expert panel knew of one local family with an affected individual with this variant that the expert panel agreed to include. There are no reports of de novo occurrences to our knowledge. Although typically homoplasmic in kindreds, the variant has been reported to segregate with features of primary mitochondrial disease in two family members from one family (PMID: 12112111) however this did not meet criteria to be considered for PP1. This variant is absent in population databases after removing sequences from individuals with mitochondrial disease (two occurrences in GenBank sequences are from individuals with mitochondrial disease; absent in gnomAD v3.1.2 and Helix dataset; PM2_supporting). The computational predictor APOGEE gives a consensus rating of pathogenic with a score of 0.60 (Min=0, Max=1), which predicts a damaging effect on gene function (PP3). An E. coli model (homoplasmic for this variant) showed only a 13% decrease in enzyme activity, which did not reach statistical significance and therefore did not meet criteria to be considered for PS3 (PMID: 19616643). In summary, this variant meets criteria to be classified as uncertain significance for primary mitochondrial disease inherited in a mitochondrial manner. In the future, once three or more unrelated cases are reported, criteria for a likely pathogenic classification would be met. This classification was approved by the NICHD/NINDS U24 Mitochondrial Disease Variant Curation Expert Panel on April 11, 2022 (PMID: 32906214): Mitochondrial DNA-specific ACMG/AMP criteria applied (PMID: 32906214): PS4_moderate, PM2_supporting, PP3. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
Apogee2	Pathogenic	0.80
Hmtvar	Pathogenic	0.68
AlphaMissense	Uncertain	0.50
BayesDel_addAF	Uncertain	0.044	T
DEOGEN2	Benign	0.017	T
LIST_S2	Uncertain	0.91	D
MutationAssessor	Uncertain	2.1	M
PROVEAN	Benign	0.050	N
GERP RS		-0.51
Varity_R		0.62

Splicing

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

Publications

LitVar

Other links and lift over

dbSNP: rs28616230; hg19: chrM-4172;