1-226965409-CGGT-C

Variant names:

• chr1-226965409-CGGT-C
• NM_020247.5:c.588+1_588+3delGTG

Variant summary

Our verdict is Likely pathogenic. The variant received 6 ACMG points: 6P and 0B. PVS1_Strong PM2

The NM_020247.5(COQ8A):​c.588+1_588+3delGTG variant causes a splice donor, splice region, intron change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. 1/1 splice prediction tools predicting alterations to normal splicing. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar.

• Frequency: Genomes: not found (cov: 33)
• Consequence: COQ8A NM_020247.5 splice_donor, splice_region, intron
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 7.56
• Publications: 0 publications found

Genes affected

COQ8A (HGNC:16812): (coenzyme Q8A) This gene encodes a mitochondrial protein similar to yeast ABC1, which functions in an electron-transferring membrane protein complex in the respiratory chain. It is not related to the family of ABC transporter proteins. Expression of this gene is induced by the tumor suppressor p53 and in response to DNA damage, and inhibiting its expression partially suppresses p53-induced apoptosis. Alternatively spliced transcript variants have been found; however, their full-length nature has not been determined. [provided by RefSeq, Jul 2008]

COQ8A Gene-Disease associations (from GenCC):

• autosomal recessive ataxia due to ubiquinone deficiency

  Inheritance: AR Classification: DEFINITIVE, SUPPORTIVE Submitted by: G2P, Orphanet
• coenzyme Q10 deficiency

  Inheritance: AR Classification: DEFINITIVE Submitted by: Illumina

ENSG00000288674 (HGNC:):

ACMG classification

Our verdict: Likely_pathogenic. The variant received 6 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, product NOT destroyed by NMD, known LOF gene, truncates exone, which is 0.21141975 fraction of the gene. Cryptic splice site detected, with MaxEntScore 5.8, offset of 27, new splice context is: gagGTagct. Cryptic site results in inframe change. If cryptic site found is not functional and variant results in exon loss, it results in inframe change.
• PM2: Very rare variant in population databases, with high coverage

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_020247.5. 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
	COQ8A	NM_020247.5	MANE Select	c.588+1_588+3delGTG		splice_donor splice_region intron	N/A	NP_064632.2

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	COQ8A	ENST00000366777.4	TSL:1 MANE Select	c.588_588+2delGGT	p.Leu197SerfsTer451	frameshift splice_donor splice_region intron	Exon 3 of 15	ENSP00000355739.3	Q8NI60-1
	COQ8A	ENST00000366778.5	TSL:1	c.432_432+2delGGT	p.Leu145SerfsTer451	frameshift splice_donor splice_region intron	Exon 3 of 15	ENSP00000355740.1	Q8NI60-3
	ENSG00000288674	ENST00000366779.6	TSL:2	n.*5315_*5315+2delGGT		splice_region non_coding_transcript_exon	Exon 20 of 32	ENSP00000355741.2

Frequencies

GnomAD3 genomes Cov.: 33

We have no GnomAD4 exomes data on this position. Probably position not covered by the project.

GnomAD4 genome Cov.: 33

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
PhyloP100		7.6

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		1.0		Details are displayed if max score is > 0.2
DS_DG_spliceai		0.86		Position offset: 31
DS_DL_spliceai		1.0		Position offset: 1

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: chr1-227153110;