Genetic Variant USB1:p.Met1fs (chr16-58001479-G-GC) – ACMG Classification: Likely_pathogenic (8 pts)

Variant summary

Our verdict is Likely pathogenic. The variant received 8 ACMG points: 8P and 0B. PVS1

The NM_024598.4(USB1):c.-1dupC(p.Met1fs) variant causes a frameshift, start lost change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000445 in 1,595,688 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: 0.000048 ( 0 hom. )

Consequence

USB1
NM_024598.4 frameshift, start_lost

Scores

Not classified

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 0.288

Publications

0 publications found

Variant links:

Genes affected

USB1 (HGNC:25792): (U6 snRNA biogenesis phosphodiesterase 1) This gene encodes a protein with several conserved domains, however, its exact function is not known. Mutations in this gene are associated with poikiloderma with neutropenia (PN), which shows phenotypic overlap with Rothmund-Thomson syndrome (RTS) caused by mutations in the RECQL4 gene. It is believed that this gene product interacts with RECQL4 protein via SMAD4 proteins, explaining the partial clinical overlap between PN and RTS. Alternatively spliced transcript variants encoding different isoforms have been noted for this gene. [provided by RefSeq, Mar 2011]

USB1 Gene-Disease associations (from GenCC):

poikiloderma with neutropenia
Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Orphanet, Labcorp Genetics (formerly Invitae), G2P
dyskeratosis congenita
Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

USB1 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_pathogenic. The variant received 8 ACMG points.

PVS1

Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant located near the start codon (<100nt), not predicted to undergo nonsense mediated mRNA decay. There are 23 pathogenic variants in the truncated region.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_024598.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
USB1	NM_024598.4	MANE Select	c.-1dupC	p.Met1fs	frameshift start_lost	Exon 1 of 7	NP_078874.2
USB1	NM_001195302.2		c.-1dupC	p.Met1fs	frameshift start_lost	Exon 1 of 6	NP_001182231.1	Q9BQ65-2
USB1	NM_001204911.2		c.-1dupC	p.Met1fs	frameshift start_lost	Exon 1 of 4	NP_001191840.1	Q9BQ65-3

Ensembl Transcripts

Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
USB1	ENST00000219281.8	TSL:1 MANE Select	c.-1dupC	p.Met1fs	frameshift start_lost	Exon 1 of 7	ENSP00000219281.3	Q9BQ65-1
USB1	ENST00000539737.6	TSL:2	c.-1dupC	p.Met1fs	frameshift start_lost	Exon 1 of 6	ENSP00000446143.2	Q9BQ65-2
USB1	ENST00000896281.1		c.-1dupC	p.Met1fs	frameshift start_lost	Exon 1 of 6	ENSP00000566340.1

Frequencies

GnomAD3 genomes

AF:

0.0000131

AC:

AN:

152230

Hom.:

Cov.:

show subpopulations

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:

0.0000294

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.00000464

AC:

AN:

215558

AF XY:

0.00000851

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000106

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000478

AC:

AN:

1443458

Hom.:

Cov.:

AF XY:

0.0000516

AC XY:

AN XY:

716452

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33066

American (AMR)

AF:

0.00

AC:

AN:

42492

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

25798

East Asian (EAS)

AF:

0.00

AC:

AN:

38638

South Asian (SAS)

AF:

0.00

AC:

AN:

83354

European-Finnish (FIN)

AF:

0.00

AC:

AN:

50944

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5704

European-Non Finnish (NFE)

AF:

0.0000625

AC:

AN:

1103856

Other (OTH)

AF:

0.00

AC:

AN:

59606

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.468

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

GnomAD4 genome

AF:

0.0000131

AC:

AN:

152230

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

74360

show subpopulations

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5.

African (AFR)

AF:

0.00

AC:

AN:

41456

American (AMR)

AF:

0.00

AC:

AN:

15288

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3470

East Asian (EAS)

AF:

0.00

AC:

AN:

5186

South Asian (SAS)

AF:

0.00

AC:

AN:

4834

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10628

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.0000294

AC:

AN:

68048

Other (OTH)

AF:

0.00

AC:

AN:

2092

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5. (p-value = 0.00233887), which strongly suggests a high chance of mosaicism in these individuals.

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.350

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Alfa

AF:

0.00

Hom.:

Bravo

AF:

0.0000189

ClinVar

ClinVar submissions as Germline

Significance:Uncertain significance

Revision:criteria provided, single submitter

View on ClinVar

Pathogenic

VUS

Benign

Condition

not provided (1)

Computational scores

Source: dbNSFP v4.9

Name

Calibrated prediction

Score

Prediction

PhyloP100

0.29

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

You must be logged in to view publications. This limit was set because tens of millions (!) of queries from AI bots are generated daily.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Variant Effect in Transcripts

RefSeq Transcripts

Ensembl Transcripts

Frequencies

Age Distribution

ClinVar

Computational scores

Splicing

Publications

Other links and lift over