chr20-17969893-CA-C

Position:

• chr20-17969893-CA-C

Variant summary

Our verdict is Likely pathogenic. Variant got 8 ACMG points: 8P and 0B. PVS1_Strong PM2 PP5_Moderate

The NM_052865.4(MGME1):​c.35del​(p.Gln12ArgfsTer30) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Pathogenic (★).

• Frequency: Genomes: not found (cov: 33)
• Consequence: MGME1 NM_052865.4 frameshift
• Clinical Significance: Pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 1.07

Genes affected

MGME1 (HGNC:16205): (mitochondrial genome maintenance exonuclease 1) The protein encoded by this gene is a nuclear-encoded mitochondrial protein necessary for the maintenance of mitochondrial genome synthesis. The encoded protein is a RecB-type exonuclease and primarily cleaves single-stranded DNA. Defects in this gene have been associated with mitochondrial DNA depletion syndrome-11. Three transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Jul 2015]

OVOL2 (HGNC:15804): (ovo like zinc finger 2) This gene encodes a member of the evolutionarily conserved ovo-like protein family. Mammalian members of this family contain a single zinc finger domain composed of a tetrad of C2H2 zinc fingers with variable N- and C-terminal extensions that contain intrinsically disordered domains. Members of this family are involved in epithelial development and differentiation. Knockout of this gene in mouse results in early embryonic lethality with phenotypes that include neurectoderm expansion, impaired vascularization, and heart anomalies. In humans, allelic variants of this gene have been associated with posterior polymorphous corneal dystrophy. [provided by RefSeq, Apr 2016]

ACMG classification

Verdict is Likely_pathogenic. Variant got 8 ACMG points.

• PVS1: Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant located near the start codon (<100nt), not predicted to undergo nonsense mediated mRNA decay. There are 12 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 20-17969893-CA-C is Pathogenic according to our data. Variant chr20-17969893-CA-C is described in ClinVar as [Pathogenic]. Clinvar id is 2041766.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
MGME1	NM_052865.4	c.35del	p.Gln12ArgfsTer30	frameshift_variant	2/5	ENST00000377710.10

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
MGME1	ENST00000377710.10	c.35del	p.Gln12ArgfsTer30	frameshift_variant	2/5	1	NM_052865.4	P1
MGME1	ENST00000377709.1	c.35del	p.Gln12ArgfsTer30	frameshift_variant	2/5	2
MGME1	ENST00000377704.4	c.35del	p.Gln12ArgfsTer30	frameshift_variant	2/3	3
OVOL2	ENST00000486776.5	n.492-12857del		intron_variant, non_coding_transcript_variant		3

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 33

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jun 27, 2022

This sequence change creates a premature translational stop signal (p.Gln12Argfs*30) in the MGME1 gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in MGME1 are known to be pathogenic (PMID: 23313956). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with MGME1-related conditions. For these reasons, this variant has been classified as Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.0		Details are displayed if max score is > 0.2

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

Publications

No publications associated with this variant yet.

Other links and lift over

hg19: chr20-17950536;