rs777593389

Positions:

• chr8-99156693-C-T

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The NM_017890.5(VPS13B):​c.2158C>T​(p.Gln720Ter) variant causes a stop gained change. The variant allele was found at a frequency of 0.0000103 in 1,461,720 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★★). Variant results in nonsense mediated mRNA decay.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.000010 (0 hom.)
• Consequence: VPS13B NM_017890.5 stop_gained
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:4
• Conservation: PhyloP100: 7.18

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]

ACMG classification

Verdict is Pathogenic. Variant got 18 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 8-99156693-C-T is Pathogenic according to our data. Variant chr8-99156693-C-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 369684.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
VPS13B	NM_017890.5	c.2158C>T	p.Gln720Ter	stop_gained	15/62	ENST00000358544.7	NP_060360.3
VPS13B	NM_152564.5	c.2158C>T	p.Gln720Ter	stop_gained	15/62	ENST00000357162.7	NP_689777.3
VPS13B	NM_015243.3	c.2158C>T	p.Gln720Ter	stop_gained	15/18		NP_056058.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
VPS13B	ENST00000358544.7	c.2158C>T	p.Gln720Ter	stop_gained	15/62	1	NM_017890.5	ENSP00000351346
VPS13B	ENST00000357162.7	c.2158C>T	p.Gln720Ter	stop_gained	15/62	1	NM_152564.5	ENSP00000349685	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000398 AC: 1 AN: 251332 Hom.: 0 AF XY: 0.00000736 AC XY: 1 AN XY: 135844

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 SAS 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: 0.0000103 AC: 15 AN: 1461720 Hom.: 0 Cov.: 30 AF XY: 0.0000124 AC XY: 9 AN XY: 727162

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.0000126

Gnomad4 OTH exome AF: 0.0000166

GnomAD4 genome Cov.: 32

ExAC AF: 0.00000824 AC: 1

EpiCase AF: 0.00

EpiControl AF: 0.0000593

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:4

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Cohen syndrome Pathogenic:4

Pathogenic, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Dec 29, 2023	This sequence change creates a premature translational stop signal (p.Gln720*) in the VPS13B gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in VPS13B are known to be pathogenic (PMID: 15141358, 16648375, 20461111). This variant is present in population databases (rs777593389, gnomAD 0.0009%). This premature translational stop signal has been observed in individual(s) with clinical features of Cohen syndrome (PMID: 26938784). In at least one individual the data is consistent with being in trans (on the opposite chromosome) from a pathogenic variant. ClinVar contains an entry for this variant (Variation ID: 369684). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. For these reasons, this variant has been classified as Pathogenic. -
Pathogenic, criteria provided, single submitter	clinical testing	Victorian Clinical Genetics Services, Murdoch Childrens Research Institute	Aug 21, 2015	This single nucleotide substitution results in a premature stop codon at position 720, NP_060360.3(VPS13B): p.(Gln720*). This is a novel variant not reported in disease or population databases. It was identified in trans with a second previously published pathogenic variant in this gene, p.(Trp963*). -
Likely pathogenic, criteria provided, single submitter	clinical testing	Counsyl	Oct 24, 2017	- -
Pathogenic, criteria provided, single submitter	clinical testing	Greenwood Genetic Center Diagnostic Laboratories, Greenwood Genetic Center	Oct 11, 2022	PVS1, PM2, PM3 -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Pathogenic	0.65
CADD	Pathogenic	38
DANN	Uncertain	1.0
Eigen	Pathogenic	1.2
Eigen_PC	Pathogenic	1.0
FATHMM_MKL	Pathogenic	0.97	D
MutationTaster	Benign	1.0	A;A;A;A
Vest4		0.98
GERP RS		5.7
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.34		Details are displayed if max score is > 0.2
DS_DL_spliceai		0.34		Position offset: 50

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

Publications

LitVar

Other links and lift over

dbSNP: rs777593389; hg19: chr8-100168921;