8-99556655-T-G

Variant names:

• chr8-99556655-T-G
• rs761273297
• NM_017890.5:c.5024+2T>G

Variant summary

Our verdict is Likely pathogenic. The variant received 6 ACMG points: 6P and 0B. PVS1_Moderate PM2 PP5_Moderate

The NM_017890.5(VPS13B):​c.5024+2T>G variant causes a splice donor, intron change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. 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 Pathogenic (★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: VPS13B NM_017890.5 splice_donor, intron
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 7.76
• Publications: 0 publications found

Genes affected

VPS13B (HGNC:2183): (vacuolar protein sorting 13 homolog B) This gene encodes a potential transmembrane protein that may function in vesicle-mediated transport and sorting of proteins within the cell. This protein may play a role in the development and the function of the eye, hematological system, and central nervous system. Mutations in this gene have been associated with Cohen syndrome. Multiple splice variants encoding distinct isoforms have been identified for this gene. [provided by RefSeq, Jul 2008]

VPS13B Gene-Disease associations (from GenCC):

• Cohen syndrome

  Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Orphanet, Myriad Women’s Health, Labcorp Genetics (formerly Invitae), G2P, Genomics England PanelApp, Laboratory for Molecular Medicine, ClinGen

ACMG classification

Our verdict: Likely_pathogenic. The variant received 6 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, product NOT destroyed by NMD, known LOF gene, truncates exone, which is 0.016902808 fraction of the gene. No cryptic splice site detected. Exon removal is inframe change.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 8-99556655-T-G is Pathogenic according to our data. Variant chr8-99556655-T-G is described in ClinVar as Pathogenic. ClinVar VariationId is 2765390.Status of the report is criteria_provided_single_submitter, 1 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_017890.5. 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
	VPS13B	NM_017890.5	MANE Plus Clinical	c.5024+2T>G		splice_donor intron	N/A	NP_060360.3
	VPS13B	NM_152564.5	MANE Select	c.4949+2T>G		splice_donor intron	N/A	NP_689777.3

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	VPS13B	ENST00000358544.7	TSL:1 MANE Plus Clinical	c.5024+2T>G		splice_donor intron	N/A	ENSP00000351346.2
	VPS13B	ENST00000357162.7	TSL:1 MANE Select	c.4949+2T>G		splice_donor intron	N/A	ENSP00000349685.2
	VPS13B	ENST00000521559.1	TSL:3	c.111-19003T>G		intron	N/A	ENSP00000428809.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

Cohen syndrome Pathogenic:1

Oct 04, 2023

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change affects a donor splice site in intron 31 of the VPS13B gene. RNA analysis indicates that disruption of this splice site induces altered splicing and likely results in a shortened protein product. This variant is not present in population databases (gnomAD no frequency). Disruption of this splice site has been observed in individual(s) with clinical features of Cohen syndrome (PMID: 34425733). Studies have shown that disruption of this splice site results in skipping of exon 31, but is expected to preserve the integrity of the reading-frame (PMID: 34425733). This variant disrupts a region of the VPS13B protein in which other variant(s) (p.Ile1611Asn) have been determined to be pathogenic (PMID: 20656880, 35690661). This suggests that this is a clinically significant region of the protein, and that variants that disrupt it are likely to be disease-causing. For these reasons, this variant has been classified as Pathogenic.

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Pathogenic	0.36
CADD	Pathogenic	32
DANN	Uncertain	0.99
Eigen	Pathogenic	1.1
Eigen_PC	Pathogenic	0.96
FATHMM_MKL	Pathogenic	0.99	D
PhyloP100		7.8
GERP RS		5.4
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		2.2
Mutation Taster		=0/100	disease causing

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.93
SpliceAI score (max)		1.0		Details are displayed if max score is > 0.2
DS_DL_spliceai		1.0		Position offset: -2

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

Other links and lift over

dbSNP: rs761273297; hg19: chr8-100568883;