15-91005693-C-T

Variant names:

• chr15-91005693-C-T
• rs774653538
• NM_018668.5:c.1030+1G>A

Variant summary

Our verdict is Pathogenic. The variant received 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The NM_018668.5(VPS33B):​c.1030+1G>A variant causes a splice donor, intron change. The variant allele was found at a frequency of 0.00000558 in 1,614,004 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Likely pathogenic (★★).

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 32)
  • Exomes 𝑓: 0.0000055 (0 hom.)
• Consequence: VPS33B NM_018668.5 splice_donor, intron
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Likely pathogenic criteria provided, multiple submitters, no conflicts P:2
• Conservation: PhyloP100: 6.92
• Publications: 1 publications found

Genes affected

VPS33B (HGNC:12712): (VPS33B late endosome and lysosome associated) Vesicle mediated protein sorting plays an important role in segregation of intracellular molecules into distinct organelles. Genetic studies in yeast have identified more than 40 vacuolar protein sorting (VPS) genes involved in vesicle transport to vacuoles. This gene is a member of the Sec-1 domain family, and encodes the human ortholog of rat Vps33b which is homologous to the yeast class C Vps33 protein. The mammalian class C vacuolar protein sorting proteins are predominantly associated with late endosomes/lysosomes, and like their yeast counterparts, may mediate vesicle trafficking steps in the endosome/lysosome pathway. Mutations in this gene are associated with arthrogryposis-renal dysfunction-cholestasis syndrome. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Jan 2014]

ENSG00000284946 (HGNC:):

VPS33B-DT (HGNC:51413): (VPS33B divergent transcript)

ACMG classification

Our verdict: Pathogenic. The variant received 18 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, LoF is a know mechanism of disease, No cryptic splice site detected. Exon removal results in frameshift change.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 15-91005693-C-T is Pathogenic according to our data. Variant chr15-91005693-C-T is described in ClinVar as Likely_pathogenic. ClinVar VariationId is 3578193.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_018668.5. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	VPS33B	NM_018668.5	MANE Select	c.1030+1G>A		splice_donor intron	N/A	NP_061138.3
	VPS33B	NM_001289148.1		c.949+1G>A		splice_donor intron	N/A	NP_001276077.1
	VPS33B	NM_001289149.1		c.757+1G>A		splice_donor intron	N/A	NP_001276078.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	VPS33B	ENST00000333371.8	TSL:1 MANE Select	c.1030+1G>A		splice_donor intron	N/A	ENSP00000327650.4
	ENSG00000284946	ENST00000643536.1		n.1030+1G>A		splice_donor intron	N/A	ENSP00000494429.1
	VPS33B	ENST00000535906.1	TSL:2	c.949+1G>A		splice_donor intron	N/A	ENSP00000444053.1

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152132 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: 0.00

GnomAD2 exomes AF: 0.00000398 AC: 1 AN: 251410 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: 0.00000880

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000547 AC: 8 AN: 1461872 Hom.: 0 Cov.: 33 AF XY: 0.00000275 AC XY: 2 AN XY: 727238

African (AFR) AF: 0.0000299 AC: 1 AN: 33480

American (AMR) AF: 0.00 AC: 0 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

East Asian (EAS) AF: 0.0000252 AC: 1 AN: 39700

South Asian (SAS) AF: 0.0000116 AC: 1 AN: 86258

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53420

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 0.00000450 AC: 5 AN: 1111990

Other (OTH) AF: 0.00 AC: 0 AN: 60396

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152132 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 74326

African (AFR) AF: 0.00 AC: 0 AN: 41408

American (AMR) AF: 0.00 AC: 0 AN: 15280

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3472

East Asian (EAS) AF: 0.00 AC: 0 AN: 5192

South Asian (SAS) AF: 0.00 AC: 0 AN: 4830

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10606

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 316

European-Non Finnish (NFE) AF: 0.0000147 AC: 1 AN: 68026

Other (OTH) AF: 0.00 AC: 0 AN: 2090

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.0000151

ExAC AF: 0.0000165 AC: 2

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Arthrogryposis, renal dysfunction, and cholestasis 1;C5774200:Keratoderma-ichthyosis-deafness syndrome, autosomal recessive;C5774311:Cholestasis, progressive familial intrahepatic, 12 Pathogenic:1

Apr 12, 2024

Fulgent Genetics, Fulgent Genetics

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

not provided Pathogenic:1

Sep 11, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change affects a donor splice site in intron 13 of the VPS33B gene. It is expected to disrupt RNA splicing. Variants that disrupt the donor or acceptor splice site typically lead to a loss of protein function (PMID: 16199547), and loss-of-function variants in VPS33B are known to be pathogenic (PMID: 15052268, 16896922). This variant is present in population databases (rs774653538, gnomAD 0.003%). This variant has not been reported in the literature in individuals affected with VPS33B-related conditions. Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic.

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.56	D
BayesDel_noAF	Pathogenic	0.45
CADD	Pathogenic	34
DANN	Uncertain	1.0
Eigen	Pathogenic	1.2
Eigen_PC	Pathogenic	1.0
FATHMM_MKL	Pathogenic	0.99	D
PhyloP100		6.9
GERP RS		5.5
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Mutation Taster		=0/100	disease causing

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.92
SpliceAI score (max)		0.93		Details are displayed if max score is > 0.2
DS_DL_spliceai		0.93		Position offset: 1

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

Other links and lift over

dbSNP: rs774653538; hg19: chr15-91548923; COSMIC: COSV60980209; COSMIC: COSV60980209;