chr8-96231081-CTTTT-C

Position:

• chr8-96231081-CTTTT-C

Variant summary

Our verdict is Uncertain significance. Variant got 5 ACMG points: 5P and 0B. PVS1_Moderate PM2 PP5

The NM_006294.5(UQCRB):​c.306_309del​(p.Arg105LysfsTer22) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000657 in 152,214 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 33)
  • Exomes 𝑓: 0.0000021 (0 hom.)
  • Failed GnomAD Quality Control
• Consequence: UQCRB NM_006294.5 frameshift
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:2 U:1
• Conservation: PhyloP100: 3.02

Genes affected

UQCRB (HGNC:12582): (ubiquinol-cytochrome c reductase binding protein) This gene encodes a subunit of the ubiquinol-cytochrome c oxidoreductase complex, which consists of one mitochondrial-encoded and 10 nuclear-encoded subunits. The protein encoded by this gene binds ubiquinone and participates in the transfer of electrons when ubiquinone is bound. This protein plays an important role in hypoxia-induced angiogenesis through mitochondrial reactive oxygen species-mediated signaling. Mutations in this gene are associated with mitochondrial complex III deficiency. Alternatively spliced transcript variants have been found for this gene. Related pseudogenes have been identified on chromosomes 1, 5 and X. [provided by RefSeq, Dec 2011]

ACMG classification

Verdict is Uncertain_significance. Variant got 5 ACMG points.

• PVS1: Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant is located in the 3'-most exon, not predicted to undergo nonsense mediated mRNA decay. Fraction of 0.0893 CDS is truncated, and there are 3 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 8-96231081-CTTTT-C is Pathogenic according to our data. Variant chr8-96231081-CTTTT-C is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 286054.We mark this variant Likely_pathogenic, oryginal submissions are: {Pathogenic=1, Uncertain_significance=1}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
UQCRB	NM_006294.5	c.306_309del	p.Arg105LysfsTer22	frameshift_variant	4/4	ENST00000287022.10
UQCRB	NM_001199975.3	c.210_213del	p.Arg73LysfsTer22	frameshift_variant	5/5
UQCRB	NM_001254752.2	c.*20_*23del		3_prime_UTR_variant	5/5
UQCRB	NR_045639.2	n.611_614del		non_coding_transcript_exon_variant	5/5

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
UQCRB	ENST00000287022.10	c.306_309del	p.Arg105LysfsTer22	frameshift_variant	4/4	1	NM_006294.5	P1

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152214 Hom.: 0 Cov.: 33

Gnomad AFR AF: 0.0000241

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.00

GnomAD4 exome Data not reliable, filtered out with message: AS_VQSR AF: 0.00000205 AC: 3 AN: 1461524 Hom.: 0 AF XY: 0.00 AC XY: 0 AN XY: 727086

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000270

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152214 Hom.: 0 Cov.: 33 AF XY: 0.00 AC XY: 0 AN XY: 74372

Gnomad4 AFR AF: 0.0000241

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.00

Gnomad4 OTH AF: 0.00

Bravo AF: 0.00000378

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:2 Uncertain:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

not provided Pathogenic:1 Uncertain:1

Pathogenic, criteria provided, single submitter	clinical testing	Eurofins Ntd Llc (ga)	Jan 25, 2016	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Aug 23, 2022	This sequence change results in a frameshift in the UQCRB gene (p.Arg105Lysfs*22). While this is not anticipated to result in nonsense mediated decay, it is expected to disrupt the last 7 amino acid(s) of the UQCRB protein and extend the protein by 14 additional amino acid residues. This variant is present in population databases (no rsID available, gnomAD 0.01%). This frameshift has been observed in individual(s) with autosomal recessive mitochondrial complex III deficiency (PMID: 12709789, 28604960). ClinVar contains an entry for this variant (Variation ID: 286054). Algorithms developed to predict the effect of variants on protein structure and function are not available or were not evaluated for this variant. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. Experimental studies have shown that this frameshift affects UQCRB function (PMID: 25446085). -

Mitochondrial complex III deficiency nuclear type 3 Pathogenic:1

Pathogenic, no assertion criteria provided

literature only

OMIM

Jul 01, 2003

- -

Computational scores

Source: dbNSFP v4.3

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

Publications

LitVar

Other links and lift over

dbSNP: rs886043294; hg19: chr8-97243309;