8-99511278-ATTC-A

Position:

• chr8-99511278-ATTC-A

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 3P and 0B. PM2 PM4_Supporting

The NM_017890.5(VPS13B):​c.4480_4482del​(p.Leu1494del) variant causes a inframe deletion change. The variant allele was found at a frequency of 0.00000684 in 1,461,750 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★). Synonymous variant affecting the same amino acid position (i.e. I1492I) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000068 (0 hom.)
• Consequence: VPS13B NM_017890.5 inframe_deletion
• Clinical Significance: Uncertain significance criteria provided, single submitter P:1 U:1
• Conservation: PhyloP100: 5.90

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 Uncertain_significance. Variant got 3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PM4: Nonframeshift variant in NON repetitive region in NM_017890.5. Strenght limited to Supporting due to length of the change: 1aa.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
VPS13B	NM_017890.5	c.4480_4482del	p.Leu1494del	inframe_deletion	29/62	ENST00000358544.7
VPS13B	NM_152564.5	c.4405_4407del	p.Leu1469del	inframe_deletion	29/62	ENST00000357162.7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
VPS13B	ENST00000357162.7	c.4405_4407del	p.Leu1469del	inframe_deletion	29/62	1	NM_152564.5	P1
VPS13B	ENST00000358544.7	c.4480_4482del	p.Leu1494del	inframe_deletion	29/62	1	NM_017890.5

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000684 AC: 10 AN: 1461750 Hom.: 0 AF XY: 0.00000963 AC XY: 7 AN XY: 727172

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.0000504

Gnomad4 SAS exome AF: 0.0000116

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000630

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

Bravo AF: 0.00000378

ClinVar

Significance: Uncertain significance

Submissions summary: Pathogenic:1 Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Cohen syndrome Pathogenic:1

Likely pathogenic, no assertion criteria provided

literature only

Juha Muilu Group; Institute for Molecular Medicine Finland (FIMM)

-

- -

not specified Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Jun 13, 2023

Variant summary: VPS13B c.4480_4482delCTT (p.Leu1494del) results in an in-frame deletion that is predicted to remove 1 amino acid from the encoded protein. The variant was absent in 251054 control chromosomes. p.Leu1494del has been reported in the literature in two related individuals affected with Cohen Syndrome who were homozygous for the variant, but carried another pathogenic upstream truncating variant on one allele, allowing evaluation of the variant in the compound heterozygous state only (Seifert_2008). These data indicate that the variant may be associated with disease. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014. Based on the evidence outlined above, the variant was classified as VUS - possibly pathogenic. -

Computational scores

Source: dbNSFP v4.3

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

LitVar

Other links and lift over

dbSNP: rs386834088; hg19: chr8-100523506;