Genetic Variant USP18:p.Thr80Ile (chr22-18160253-C-T) – ACMG Classification: Uncertain_significance (2 pts)

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 2P and 0B. PM2

The NM_017414.4(USP18):c.239C>T(p.Thr80Ile) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000489 in 1,614,098 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★).

Frequency

Genomes: 𝑓 0.000053 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000049 ( 0 hom. )

Consequence

USP18
NM_017414.4 missense

Scores

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 2.84

Variant links:

Genes affected

USP18 (HGNC:12616): (ubiquitin specific peptidase 18) The protein encoded by this gene belongs to the ubiquitin-specific proteases (UBP) family of enzymes that cleave ubiquitin from ubiquitinated protein substrates. It is highly expressed in liver and thymus, and is localized to the nucleus. This protein efficiently cleaves only ISG15 (a ubiquitin-like protein) fusions, and deletion of this gene in mice results in a massive increase of ISG15 conjugates in tissues, indicating that this protein is a major ISG15-specific protease. Mice lacking this gene are also hypersensitive to interferon, suggesting a function of this protein in downregulating interferon responses, independent of its isopeptidase activity towards ISG15. [provided by RefSeq, Sep 2011]

USP18 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 2 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
USP18	NM_017414.4 link	c.239C>T	p.Thr80Ile	missense_variant	Exon 3 of 11	ENST00000215794.8	NP_059110.2	Q9UMW8-1
USP18	XM_006724074.4 link	c.17C>T	p.Thr6Ile	missense_variant	Exon 2 of 10		XP_006724137.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
USP18	ENST00000215794.8 link	c.239C>T	p.Thr80Ile	missense_variant	Exon 3 of 11	1	NM_017414.4	ENSP00000215794.7		Q9UMW8-1
USP18	ENST00000699060.1 link	c.239C>T	p.Thr80Ile	missense_variant	Exon 3 of 10			ENSP00000514107.1		A0A8V8TMN0

Frequencies

GnomAD3 genomes

AF:

0.0000526

AC:

AN:

152188

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.000131

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00318

Gnomad NFE

AF:

0.0000588

Gnomad OTH

AF:

0.000478

GnomAD3 exomes

AF:

0.0000437

AC:

AN:

251490

Hom.:

AF XY:

0.0000662

AC XY:

AN XY:

135920

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.0000289

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.0000653

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000615

Gnomad OTH exome

AF:

0.000163

GnomAD4 exome

AF:

0.0000486

AC:

AN:

1461790

Hom.:

Cov.:

AF XY:

0.0000440

AC XY:

AN XY:

727200

show subpopulations

Gnomad4 AFR exome

AF:

0.0000597

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.0000580

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000360

Gnomad4 OTH exome

AF:

0.000166

GnomAD4 genome

AF:

0.0000525

AC:

AN:

152308

Hom.:

Cov.:

AF XY:

0.0000671

AC XY:

AN XY:

74470

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.000131

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000588

Gnomad4 OTH

AF:

0.000473

Alfa

AF:

0.0000758

Hom.:

Bravo

AF:

0.0000945

ESP6500AA

AF:

0.00

AC:

ESP6500EA

AF:

0.000349

AC:

ExAC

AF:

0.0000494

AC:

Asia WGS

AF:

0.000289

AC:

AN:

3478

EpiCase

AF:

0.0000545

EpiControl

AF:

0.000237

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

Inborn genetic diseases

Uncertain:1

Nov 08, 2024

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.239C>T (p.T80I) alteration is located in exon 3 (coding exon 2) of the USP18 gene. This alteration results from a C to T substitution at nucleotide position 239, causing the threonine (T) at amino acid position 80 to be replaced by an isoleucine (I). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.22

BayesDel_addAF

Benign

-0.29

BayesDel_noAF

Benign

-0.45

CADD

Benign

DANN

Uncertain

1.0

DEOGEN2

Benign

0.20

Eigen

Benign

0.032

Eigen_PC

Benign

0.031

FATHMM_MKL

Uncertain

0.78

LIST_S2

Benign

0.82

M_CAP

Benign

0.023

MetaRNN

Uncertain

0.51

MetaSVM

Benign

-0.99

PrimateAI

Uncertain

0.60

PROVEAN

Uncertain

-2.7

REVEL

Benign

0.13

Sift

Benign

0.11

Sift4G

Uncertain

0.057

Polyphen

0.73

Vest4

0.62

MVP

0.47

MPC

1.3

ClinPred

0.17

GERP RS

3.6

Varity_R

0.12

gMVP

0.44

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

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over