4-83284849-T-C

Variant names:

• chr4-83284849-T-C
• rs987047651
• ENST00000311469.9:c.66A>G
• COQ2 p.Arg22Arg

Variant summary

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

The NM_015697.9(COQ2):​c.66A>G​(p.Arg22Arg) 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. R22R) has been classified as Likely benign.

• Frequency: Genomes: not found (cov: 32)
• Consequence: COQ2 NM_015697.9 synonymous
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: -0.298
• 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: G2P, Labcorp Genetics (formerly Invitae)
• 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=-0.92).
• BP7: Synonymous conserved (PhyloP=-0.298 with no splicing effect.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_015697.9. 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_015697.9		c.66A>G	p.Arg22Arg	synonymous	Exon 1 of 7	NP_056512.5
	COQ2	NM_001358921.2	MANE Select	c.-85A>G		upstream_gene	N/A	NP_001345850.1	Q96H96-1

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	COQ2	ENST00000311469.9	TSL:1	c.66A>G	p.Arg22Arg	synonymous	Exon 1 of 7	ENSP00000310873.4	Q96H96-4
	COQ2	ENST00000647002.2	MANE Select	c.-85A>G		upstream_gene	N/A	ENSP00000495761.2	Q96H96-1
	COQ2	ENST00000311461.7	TSL:5	c.-85A>G		upstream_gene	N/A	ENSP00000311835.7	Q96H96-3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 33

GnomAD4 genome Cov.: 32

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000756

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.92
CADD	Benign	2.7
DANN	Benign	0.48
PhyloP100		-0.30
PromoterAI		-0.0074	Neutral

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

dbSNP: rs987047651;

hg19: chr4-84206002;