chrX-77899598-G-C

Position:

• chrX-77899598-G-C

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM2 PP5_Moderate

The NM_001866.3(COX7B):​c.40+5G>C variant causes a splice region, intron change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. 2/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Likely pathogenic (★).

• Frequency: Genomes: not found (cov: 23)
• Consequence: COX7B NM_001866.3 splice_region, intron
• Scores: Splicing: ADA: 0.9933
• Clinical Significance: Likely pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 4.37

Genes affected

COX7B (HGNC:2291): (cytochrome c oxidase subunit 7B) Cytochrome c oxidase (COX), the terminal component of the mitochondrial respiratory chain, catalyzes the electron transfer from reduced cytochrome c to oxygen. This component is a heteromeric complex consisting of 3 catalytic subunits encoded by mitochondrial genes and multiple structural subunits encoded by nuclear genes. The mitochondrially-encoded subunits function in electron transfer, and the nuclear-encoded subunits may function in the regulation and assembly of the complex. This nuclear gene encodes subunit VIIb, which is highly similar to bovine COX VIIb protein and is found in all tissues. This gene may have several pseudogenes on chromosomes 1, 2, 20 and 22. [provided by RefSeq, Jun 2011]

ACMG classification

Verdict is Uncertain_significance. Variant got 4 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant X-77899598-G-C is Pathogenic according to our data. Variant chrX-77899598-G-C is described in ClinVar as [Likely_pathogenic]. Clinvar id is 449642.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
COX7B	NM_001866.3	c.40+5G>C		splice_region_variant, intron_variant		ENST00000650309.2	NP_001857.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
COX7B	ENST00000650309.2	c.40+5G>C		splice_region_variant, intron_variant			NM_001866.3	ENSP00000497474.1
COX7B	ENST00000373335.4	c.-145+5G>C		splice_region_variant, intron_variant		2		ENSP00000496880.1
COX7B	ENST00000475465.1	c.40+5G>C		splice_region_variant, intron_variant		2		ENSP00000497958.1
COX7B	ENST00000647835.1	c.40+5G>C		splice_region_variant, intron_variant				ENSP00000497517.1

Frequencies

GnomAD3 genomes Cov.: 23

GnomAD4 exome Cov.: 29

GnomAD4 genome Cov.: 23

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

GeneDx

Feb 03, 2016

The c.40+5G>C pathogenic variant in the COX7B gene has not been reported previously as a pathogenic variant nor as a benign variant, to our knowledge. This variant reduces the quality of the splice donor site in intron 1, and is expected to cause abnormal gene splicing. The c.40+5G>C variant was not observed in approximately 6500 individuals of European and African American ancestry in the NHLBI Exome Sequencing Project, indicating it is not a common benign variant in these populations. The de novo c.40+5G>C variant is a strong candidate for a pathogenic variant, however the possibility it may be a rare benign variant cannot be excluded. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.21
CADD	Benign	22
DANN	Benign	0.91

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	0.99
dbscSNV1_RF	Pathogenic	0.79
SpliceAI score (max)		0.030		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: rs1557220472; hg19: chrX-77155095;