1-226965719-C-T
Variant summary
Our verdict is Pathogenic. Variant got 16 ACMG points: 16P and 0B. PM2PM5PP3_StrongPP5_Very_Strong
The NM_020247.5(COQ8A):c.637C>T(p.Arg213Trp) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000806 in 1,613,776 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R213G) has been classified as Likely pathogenic.
Frequency
Consequence
NM_020247.5 missense
Scores
Clinical Significance
Conservation
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ACMG classification
Verdict is Pathogenic. Variant got 16 ACMG points.
Transcripts
RefSeq
Ensembl
Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | TSL | MANE | Protein | Appris | UniProt |
---|---|---|---|---|---|---|---|---|---|---|
COQ8A | ENST00000366777.4 | c.637C>T | p.Arg213Trp | missense_variant | Exon 4 of 15 | 1 | NM_020247.5 | ENSP00000355739.3 | ||
ENSG00000288674 | ENST00000366779.6 | n.*5364C>T | non_coding_transcript_exon_variant | Exon 21 of 32 | 2 | ENSP00000355741.2 | ||||
ENSG00000288674 | ENST00000366779.6 | n.*5364C>T | 3_prime_UTR_variant | Exon 21 of 32 | 2 | ENSP00000355741.2 |
Frequencies
GnomAD3 genomes AF: 0.0000131 AC: 2AN: 152210Hom.: 0 Cov.: 33
GnomAD3 exomes AF: 0.00000798 AC: 2AN: 250584Hom.: 0 AF XY: 0.00 AC XY: 0AN XY: 135714
GnomAD4 exome AF: 0.00000753 AC: 11AN: 1461566Hom.: 0 Cov.: 32 AF XY: 0.00000825 AC XY: 6AN XY: 727070
GnomAD4 genome AF: 0.0000131 AC: 2AN: 152210Hom.: 0 Cov.: 33 AF XY: 0.00 AC XY: 0AN XY: 74354
ClinVar
Submissions by phenotype
Autosomal recessive ataxia due to ubiquinone deficiency Pathogenic:3Other:1
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The variant is observed at an extremely low frequency in the gnomAD v2.1.1 dataset (total allele frequency: 0.001%). In silico tool predictions suggest damaging effect of the variant on gene or gene product (REVEL: 0.61; 3Cnet: 0.91). Same nucleotide change resulting in same amino acid change has been previously reported to be associated with COQ8A related disorder (ClinVar ID: VCV000003637 / PMID: 18319072). Different missense changes at the same codon (p.Arg213Gln, p.Arg213Gly) have been reported as pathogenic/likely pathogenic with strong evidence (ClinVar ID: VCV000666357, VCV000806371 / PMID: 32337771, 34712575). Therefore, this variant is classified as Likely pathogenic according to the recommendation of ACMG/AMP guideline. -
This variant was previously reported in patients with coenzyme Q10 deficiency [PMID: 18319072, 22036850] and was classified as pathogenic [PMID: 28125198]. Functional studies using site-directed mutagenesis revealed that the cells harboring mutant in yeast resulted in a respiratory phenotype with no or decreased growth on glycerol medium and a severe reduction in ubiquinone synthesis [PMID: 18319072]. -
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not provided Pathogenic:1
This sequence change replaces arginine, which is basic and polar, with tryptophan, which is neutral and slightly polar, at codon 213 of the COQ8A protein (p.Arg213Trp). This variant is present in population databases (rs119468005, gnomAD 0.01%). This missense change has been observed in individual(s) with COQ8A-related condition (PMID: 18319072). In at least one individual the data is consistent with being in trans (on the opposite chromosome) from a pathogenic variant. It has also been observed to segregate with disease in related individuals. ClinVar contains an entry for this variant (Variation ID: 3637). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) has been performed at Invitae for this missense variant, however the output from this modeling did not meet the statistical confidence thresholds required to predict the impact of this variant on COQ8A protein function. Experimental studies have shown that this missense change affects COQ8A function (PMID: 18319072). This variant disrupts the p.Arg213 amino acid residue in COQ8A. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 32337771). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. For these reasons, this variant has been classified as Pathogenic. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at