1-244842006-G-T

Variant summary

Our verdict is Uncertain significance. Variant got 5 ACMG points: 5P and 0B. PM1 PM2 PP3

The NM_198076.6(COX20):c.105G>T(p.Leu35Phe) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000685 in 1,460,188 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 Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: COX20 NM_198076.6 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: -1.25

Genes affected

COX20 (HGNC:26970): (cytochrome c oxidase assembly factor COX20) This gene encodes a protein that plays a role in the assembly of cytochrome C oxidase, an important component of the respiratory pathway. It contains two transmembrane helices and localizes to the mitochondrial membrane. Mutations in this gene can cause mitochondrial complex IV deficiency, which results in ataxia and muscle hypotonia. There are multiple pseudogenes for this gene. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Aug 2015]

HNRNPU (HGNC:5048): (heterogeneous nuclear ribonucleoprotein U) This gene encodes a member of a family of proteins that bind nucleic acids and function in the formation of ribonucleoprotein complexes in the nucleus with heterogeneous nuclear RNA (hnRNA). The encoded protein has affinity for both RNA and DNA, and binds scaffold-attached region (SAR) DNA. Mutations in this gene have been associated with epileptic encephalopathy, early infantile, 54. A pseudogene of this gene has been identified on chromosome 14. [provided by RefSeq, Jun 2017]

ACMG classification

Verdict is Uncertain_significance. Variant got 5 ACMG points.

• PM1: In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 5 uncertain in NM_198076.6
• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.838

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
COX20	NM_198076.6	c.105G>T	p.Leu35Phe	missense_variant	2/4	ENST00000411948.7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
COX20	ENST00000411948.7	c.105G>T	p.Leu35Phe	missense_variant	2/4	1	NM_198076.6	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.85e-7 AC: 1 AN: 1460188 Hom.: 0 Cov.: 28 AF XY: 0.00000138 AC XY: 1 AN XY: 726486

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.0000252

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Mar 23, 2022

This variant is not present in population databases (gnomAD no frequency). 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. Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Probably Damaging"; Align-GVGD: "Class C15"). This variant has not been reported in the literature in individuals affected with COX20-related conditions. This sequence change replaces leucine, which is neutral and non-polar, with phenylalanine, which is neutral and non-polar, at codon 35 of the COX20 protein (p.Leu35Phe). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.34
BayesDel_addAF	Pathogenic	0.32	D
BayesDel_noAF	Pathogenic	0.23
Cadd	Benign	8.1
Dann	Uncertain	0.99
DEOGEN2	Uncertain	0.59	D;.
Eigen	Benign	-0.63
Eigen_PC	Benign	-0.99
FATHMM_MKL	Benign	0.16	N
LIST_S2	Uncertain	0.90	D;D
M_CAP	Benign	0.017	T
MetaRNN	Pathogenic	0.84	D;D
MetaSVM	Uncertain	-0.040	T
MutationAssessor	Uncertain	2.9	M;.
MutationTaster	Benign	0.77	N;N
PrimateAI	Uncertain	0.55	T
PROVEAN	Uncertain	-3.8	D;D
REVEL	Uncertain	0.51
Sift	Pathogenic	0.0	D;D
Sift4G	Uncertain	0.0080	D;D
Polyphen		1.0	D;.
Vest4		0.90
MutPred		0.64		Gain of sheet (P = 0.1208);.;
MVP		0.030
MPC		0.24
ClinPred		1.0	D
GERP RS		-12
Varity_R		0.73
gMVP		0.61

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

No publications associated with this variant yet.

Other links and lift over

hg19: chr1-245005308;