4-83284576-C-G

Variant names:

• chr4-83284576-C-G
• NM_001358921.2:c.189G>C
• COQ2 p.Val63Val

Variant summary

Our verdict is Likely benign. The variant received -3 ACMG points: 2P and 5B. PM2 BP4_Strong BP7

The NM_001358921.2(COQ2):​c.189G>C​(p.Val63Val) 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. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Synonymous variant affecting the same amino acid position (i.e. V63V) has been classified as Likely benign.

• Frequency: Genomes: not found (cov: 34)
• Consequence: COQ2 NM_001358921.2 synonymous
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: -4.63
• Publications: 0 publications found

Genes affected

COQ2 (HGNC:25223): (coenzyme Q2, polyprenyltransferase) This gene encodes an enzyme that functions in the final steps in the biosynthesis of CoQ (ubiquinone), a redox carrier in the mitochondrial respiratory chain and a lipid-soluble antioxidant. This enzyme, which is part of the coenzyme Q10 pathway, catalyzes the prenylation of parahydroxybenzoate with an all-trans polyprenyl group. Mutations in this gene cause coenzyme Q10 deficiency, a mitochondrial encephalomyopathy, and also COQ2 nephropathy, an inherited form of mitochondriopathy with primary renal involvement. [provided by RefSeq, Oct 2009]

COQ2 Gene-Disease associations (from GenCC):

• coenzyme Q10 deficiency, primary, 1

  Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), G2P
• mitochondrial disease

  Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen
• multiple system atrophy

  Inheritance: AR Classification: MODERATE Submitted by: Genomics England PanelApp
• Leigh syndrome with nephrotic syndrome

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Likely_benign. The variant received -3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.76).
• BP7: Synonymous conserved (PhyloP=-4.63 with no splicing effect.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_001358921.2. 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
	COQ2	NM_001358921.2	MANE Select	c.189G>C	p.Val63Val	synonymous	Exon 1 of 7	NP_001345850.1	Q96H96-1
	COQ2	NM_015697.9		c.339G>C	p.Val113Val	synonymous	Exon 1 of 7	NP_056512.5

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	COQ2	ENST00000647002.2	MANE Select	c.189G>C	p.Val63Val	synonymous	Exon 1 of 7	ENSP00000495761.2	Q96H96-1
	COQ2	ENST00000311469.9	TSL:1	c.339G>C	p.Val113Val	synonymous	Exon 1 of 7	ENSP00000310873.4	Q96H96-4
	COQ2	ENST00000311461.7	TSL:5	c.189G>C	p.Val63Val	synonymous	Exon 1 of 7	ENSP00000311835.7	Q96H96-3

Frequencies

GnomAD3 genomes Cov.: 34

GnomAD4 exome Cov.: 84

GnomAD4 genome Cov.: 34

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.76
CADD	Benign	0.13
DANN	Benign	0.57
PhyloP100		-4.6
PromoterAI		0.036	Neutral
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.6

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

MaxEntScan Visualizer can be used to analyze the impact of this mutation on the neighboring sequence.

Other links and lift over

hg19: chr4-84205729;