Genetic Variant USB1:p.Met1? (chr16-58001484-A-T) – ACMG Classification: Uncertain_significance (4 pts)

Variant summary

Our verdict is Uncertain significance. The variant received 4 ACMG points: 4P and 0B. PVS1_ModeratePM2

The NM_024598.4(USB1):c.1A>T(p.Met1?) variant causes a initiator codon change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000188 in 1,598,740 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar.

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 32)

Exomes 𝑓: 6.9e-7 ( 0 hom. )

Consequence

USB1
NM_024598.4 initiator_codon

Scores

Clinical Significance

Not reported in ClinVar

Conservation

PhyloP100: 0.166

Publications

1 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: Uncertain_significance. The variant received 4 ACMG points.

PVS1

Start lost variant, next in-frame start position is after 1 pathogenic variants. Next in-frame start position is after 22 codons. Genomic position: 58001547. Lost 0.080 part of the original CDS.

PM2

Very rare variant in population databases, with high coverage;

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.1A>T	p.Met1?	initiator_codon	Exon 1 of 7	NP_078874.2
USB1	NM_001195302.2		c.1A>T	p.Met1?	initiator_codon	Exon 1 of 6	NP_001182231.1	Q9BQ65-2
USB1	NM_001204911.2		c.1A>T	p.Met1?	initiator_codon	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.1A>T	p.Met1?	initiator_codon	Exon 1 of 7	ENSP00000219281.3	Q9BQ65-1
USB1	ENST00000561568.6	TSL:4	c.-46A>T		5_prime_UTR_premature_start_codon_gain	Exon 1 of 7	ENSP00000457322.2	H3BTT8
USB1	ENST00000539737.6	TSL:2	c.1A>T	p.Met1?	initiator_codon	Exon 1 of 6	ENSP00000446143.2	Q9BQ65-2

Frequencies

GnomAD3 genomes

AF:

0.0000131

AC:

AN:

152168

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:

0.00

AC:

AN:

220058

AF XY:

0.00

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:

0.00

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

6.91e-7

AC:

AN:

1446572

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

718266

show subpopulations

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

African (AFR)

AF:

0.00

AC:

AN:

33136

American (AMR)

AF:

0.00

AC:

AN:

42928

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

25862

East Asian (EAS)

AF:

0.00

AC:

AN:

38876

South Asian (SAS)

AF:

0.00

AC:

AN:

83742

European-Finnish (FIN)

AF:

0.00

AC:

AN:

51194

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5722

European-Non Finnish (NFE)

AF:

9.05e-7

AC:

AN:

1105420

Other (OTH)

AF:

0.00

AC:

AN:

59692

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.375

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:

152168

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

74338

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

41440

American (AMR)

AF:

0.00

AC:

AN:

15282

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3468

East Asian (EAS)

AF:

0.00

AC:

AN:

5174

South Asian (SAS)

AF:

0.00

AC:

AN:

4836

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10616

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.0000294

AC:

AN:

68034

Other (OTH)

AF:

0.00

AC:

AN:

2090

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.425

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Genome 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

Alfa

AF:

0.00

Hom.:

Bravo

AF:

0.0000151

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name

Calibrated prediction

Score

Prediction

BayesDel_addAF

Pathogenic

0.25

BayesDel_noAF

Uncertain

0.13

CADD

Benign

(source)

DANN

Uncertain

0.98

DEOGEN2

Benign

0.016

Eigen

Benign

0.089

Eigen_PC

Benign

0.092

FATHMM_MKL

Benign

0.15

LIST_S2

Uncertain

0.90

M_CAP

Pathogenic

0.63

MetaRNN

Pathogenic

0.98

MetaSVM

Benign

-0.82

PhyloP100

0.17

PROVEAN

Benign

-0.77

REVEL

Benign

0.27

Sift

Pathogenic

0.0

Sift4G

Benign

0.36

Polyphen

0.82

Vest4

0.64

MutPred

0.99

Gain of stability (P = 0.2424)

MVP

0.29

ClinPred

0.99

GERP RS

4.9

PromoterAI

-0.12

Neutral

(source)

Varity_R

0.95

gMVP

0.42

Mutation Taster

=27/173

disease causing

(source)

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

Age Distribution

ClinVar

Computational scores

Splicing

Publications

Other links and lift over