1-244841989-G-A

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM1 PM2

The NM_198076.6(COX20):c.88G>A(p.Ala30Thr) variant causes a missense change. The variant allele was found at a frequency of 0.0000273 in 1,611,244 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: 𝑓 0.000013 (0 hom., cov: 32)
  • Exomes 𝑓: 0.000029 (0 hom.)
• Consequence: COX20 NM_198076.6 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 5.08

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 4 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, 4 uncertain in NM_198076.6
• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
COX20	NM_198076.6	c.88G>A	p.Ala30Thr	missense_variant	2/4	ENST00000411948.7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
COX20	ENST00000411948.7	c.88G>A	p.Ala30Thr	missense_variant	2/4	1	NM_198076.6	P1

Frequencies

GnomAD3 genomes AF: 0.0000132 AC: 2 AN: 151856 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

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: 0.0000147

Gnomad OTH AF: 0.000479

GnomAD3 exomes AF: 0.0000478 AC: 12 AN: 251064 Hom.: 0 AF XY: 0.0000368 AC XY: 5 AN XY: 135772

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.000174

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.0000327

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000440

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000288 AC: 42 AN: 1459388 Hom.: 0 Cov.: 28 AF XY: 0.0000317 AC XY: 23 AN XY: 726134

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.000112

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.0000581

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.0000261

Gnomad4 OTH exome AF: 0.0000498

GnomAD4 genome AF: 0.0000132 AC: 2 AN: 151856 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 74144

Gnomad4 AFR AF: 0.00

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: 0.0000147

Gnomad4 OTH AF: 0.000479

Bravo AF: 0.00000378

ExAC AF: 0.0000412 AC: 5

EpiCase AF: 0.0000545

EpiControl AF: 0.0000593

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

Aug 01, 2022

This sequence change replaces alanine, which is neutral and non-polar, with threonine, which is neutral and polar, at codon 30 of the COX20 protein (p.Ala30Thr). This variant is present in population databases (rs759186431, gnomAD 0.02%). This variant has not been reported in the literature in individuals affected with COX20-related conditions. 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: "Tolerated"; PolyPhen-2: "Probably Damaging"; Align-GVGD: "Class C0"). 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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.34
BayesDel_addAF	Uncertain	0.076	D
BayesDel_noAF	Pathogenic	0.14
Cadd	Uncertain	25
Dann	Uncertain	1.0
DEOGEN2	Benign	0.34	T;.
Eigen	Uncertain	0.64
Eigen_PC	Uncertain	0.59
FATHMM_MKL	Uncertain	0.95	D
LIST_S2	Uncertain	0.93	D;D
M_CAP	Benign	0.022	T
MetaRNN	Uncertain	0.68	D;D
MetaSVM	Uncertain	-0.18	T
MutationAssessor	Uncertain	2.6	M;.
MutationTaster	Benign	1.0	D;D
PrimateAI	Benign	0.47	T
PROVEAN	Benign	-2.0	N;N
REVEL	Uncertain	0.30
Sift	Benign	0.17	T;T
Sift4G	Uncertain	0.054	T;D
Polyphen		1.0	D;.
Vest4		0.76
MutPred		0.53		Gain of glycosylation at A30 (P = 0.0134);.;
MVP		0.29
MPC		0.23
ClinPred		0.31	T
GERP RS		5.0
Varity_R		0.16
gMVP		0.52

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.020		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: rs759186431; hg19: chr1-245005291;