20-17969871-G-C

Variant names:

• chr20-17969871-G-C
• rs746885927
• NM_052865.4:c.12G>C

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_052865.4(MGME1):​c.12G>C​(p.Lys4Asn) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000144 in 1,455,800 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 14/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.000014 (0 hom.)
• Consequence: MGME1 NM_052865.4 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 1.46

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 Uncertain_significance. Variant got 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.1680601).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
MGME1	NM_052865.4	c.12G>C	p.Lys4Asn	missense_variant	Exon 2 of 5	ENST00000377710.10	NP_443097.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
MGME1	ENST00000377710.10	c.12G>C	p.Lys4Asn	missense_variant	Exon 2 of 5	1	NM_052865.4	ENSP00000366939.5

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD3 exomes AF: 0.0000285 AC: 7 AN: 245526 Hom.: 0 AF XY: 0.0000376 AC XY: 5 AN XY: 133140

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000304

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.0000336

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000447

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000144 AC: 21 AN: 1455800 Hom.: 0 Cov.: 31 AF XY: 0.0000207 AC XY: 15 AN XY: 724420

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.0000234

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.0000702

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.0000117

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

Bravo AF: 0.0000227

ExAC AF: 0.0000330 AC: 4

EpiCase AF: 0.00

EpiControl AF: 0.000119

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Inborn genetic diseases Uncertain:1

Oct 10, 2023

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.12G>C (p.K4N) alteration is located in exon 2 (coding exon 1) of the MGME1 gene. This alteration results from a G to C substitution at nucleotide position 12, causing the lysine (K) at amino acid position 4 to be replaced by an asparagine (N). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

not provided Uncertain:1

Apr 21, 2023

GeneDx

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant does not alter protein structure/function; Has not been previously published as pathogenic or benign to our knowledge -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.17
BayesDel_addAF	Benign	-0.32	T
BayesDel_noAF	Benign	-0.52
CADD	Benign	19
DANN	Uncertain	0.99
DEOGEN2	Benign	0.012	T;T;T
Eigen	Benign	0.019
Eigen_PC	Benign	-0.017
FATHMM_MKL	Benign	0.55	D
LIST_S2	Benign	0.53	T;T;T
M_CAP	Benign	0.047	D
MetaRNN	Benign	0.17	T;T;T
MetaSVM	Benign	-0.88	T
MutationAssessor	Uncertain	2.6	M;.;.
PrimateAI	Benign	0.40	T
PROVEAN	Benign	-1.3	N;N;N
REVEL	Benign	0.059
Sift	Uncertain	0.0060	D;D;D
Sift4G	Uncertain	0.013	D;D;D
Polyphen		0.88	P;.;.
Vest4		0.36
MutPred		0.28		Loss of methylation at K4 (P = 0.0313);Loss of methylation at K4 (P = 0.0313);Loss of methylation at K4 (P = 0.0313);
MVP		0.60
MPC		0.13
ClinPred		0.28	T
GERP RS		3.7
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1
Varity_R		0.13
gMVP		0.24

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.020		Details are displayed if max score is > 0.2

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

Publications

LitVar

Other links and lift over

dbSNP: rs746885927; hg19: chr20-17950514;