20-17969940-T-G

Variant names:

• chr20-17969940-T-G
• rs754203244
• NM_052865.4:c.81T>G

Variant summary

Our verdict is Likely benign. The variant received -5 ACMG points: 2P and 7B. PM2 BP4_Strong BP6_Moderate BP7

The NM_052865.4(MGME1):​c.81T>G​(p.Ala27Ala) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★).

• Frequency: Genomes: not found (cov: 33)
• Consequence: MGME1 NM_052865.4 synonymous
• Clinical Significance: Likely benign criteria provided, single submitter B:1
• Conservation: PhyloP100: 0.705
• Publications: 0 publications found

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]

OVOL2 Gene-Disease associations (from GenCC):

• posterior polymorphous corneal dystrophy 1

  Inheritance: AD Classification: DEFINITIVE, STRONG, LIMITED Submitted by: G2P, Ambry Genetics, Labcorp Genetics (formerly Invitae)
• congenital hereditary endothelial dystrophy type I

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• posterior polymorphous corneal dystrophy

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Likely_benign. The variant received -5 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.81).
• BP6: Variant 20-17969940-T-G is Benign according to our data. Variant chr20-17969940-T-G is described in ClinVar as Likely_benign. ClinVar VariationId is 1942428.Status of the report is criteria_provided_single_submitter, 1 stars.
• BP7: Synonymous conserved (PhyloP=0.705 with no splicing effect.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_052865.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	MGME1	NM_052865.4	MANE Select	c.81T>G	p.Ala27Ala	synonymous	Exon 2 of 5	NP_443097.1	Q9BQP7
	MGME1	NM_001310338.2		c.81T>G	p.Ala27Ala	synonymous	Exon 2 of 6	NP_001297267.1
	MGME1	NM_001363738.2		c.81T>G	p.Ala27Ala	synonymous	Exon 2 of 5	NP_001350667.1	Q5QPE8

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	MGME1	ENST00000377710.10	TSL:1 MANE Select	c.81T>G	p.Ala27Ala	synonymous	Exon 2 of 5	ENSP00000366939.5	Q9BQP7
	MGME1	ENST00000948803.1		c.81T>G	p.Ala27Ala	synonymous	Exon 1 of 5	ENSP00000618862.1
	MGME1	ENST00000895985.1		c.81T>G	p.Ala27Ala	synonymous	Exon 1 of 5	ENSP00000566044.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD2 exomes AF: 0.00000398 AC: 1 AN: 251390 AF XY: 0.00000736

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.000163

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 33

ClinVar

ClinVar submissions

Significance: Likely benign

Revision: criteria provided, single submitter

Pathogenic	VUS	Benign	Condition
-	-	1	not provided (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.81
CADD	Benign	8.6
DANN	Benign	0.61
PhyloP100		0.70
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7

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

Other links and lift over

dbSNP: rs754203244; hg19: chr20-17950583;