chr5-83537005-A-C

Position:

• chr5-83537005-A-C

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1_Strong PM2 PP3_Strong PP5_Very_Strong

The NM_004385.5(VCAN):​c.4004-2A>C variant causes a splice acceptor change. 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: VCAN NM_004385.5 splice_acceptor
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:2
• Conservation: PhyloP100: 6.03

Genes affected

VCAN (HGNC:2464): (versican) This gene is a member of the aggrecan/versican proteoglycan family. The protein encoded is a large chondroitin sulfate proteoglycan and is a major component of the extracellular matrix. This protein is involved in cell adhesion, proliferation, proliferation, migration and angiogenesis and plays a central role in tissue morphogenesis and maintenance. Mutations in this gene are the cause of Wagner syndrome type 1. Multiple transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Aug 2009]

VCAN-AS1 (HGNC:40163): (VCAN antisense RNA 1)

ACMG classification

Verdict is Pathogenic. Variant got 18 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, product NOT destroyed by NMD, known LOF gene, truncates exone, which is 0.5162398 fraction of the gene. Cryptic splice site detected, with MaxEntScore 6.2, offset of -26, new splice context is: tgccaaattttctatttaAGtat. Cryptic site results in frameshift change. If cryptic site found is not functional and variant results in exon loss, it results in inframe change.
• PM2: Very rare variant in population databases, with high coverage
• PP3: Splicing scoreres supports a deletorius effect: Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF, max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.
• PP5: Variant 5-83537005-A-C is Pathogenic according to our data. Variant chr5-83537005-A-C is described in ClinVar as [Pathogenic]. Clinvar id is 813123.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr5-83537005-A-C is described in Lovd as [Likely_pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
VCAN	NM_004385.5	c.4004-2A>C		splice_acceptor_variant		ENST00000265077.8
VCAN-AS1	NR_136215.1	n.285-2832T>G		intron_variant, non_coding_transcript_variant

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
VCAN	ENST00000265077.8	c.4004-2A>C		splice_acceptor_variant		1	NM_004385.5

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 29

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Wagner syndrome Pathogenic:1

Pathogenic, criteria provided, single submitter

research

Molecular Genetics Laboratory, Institute for Ophthalmic Research

Jan 09, 2020

- -

not provided Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Dec 12, 2022

Disruption of this splice site has been observed in individuals with Wagner syndrome (PMID: 16043844, 21738396). It has also been observed to segregate with disease in related individuals. For these reasons, this variant has been classified as Pathogenic. Studies have shown that disruption of this splice site results in the activation of a cryptic splice site in exon 8 (PMID: 16043844, 16877430, 21738396). ClinVar contains an entry for this variant (Variation ID: 813123). This variant is not present in population databases (gnomAD no frequency). This sequence change affects an acceptor splice site in intron 7 of the VCAN gene. RNA analysis indicates that disruption of this splice site induces altered splicing and likely results in the loss of 13 amino acid residue(s), but is expected to preserve the integrity of the reading-frame. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Pathogenic	0.23
CADD	Pathogenic	34
DANN	Uncertain	0.99
Eigen	Pathogenic	1.1
Eigen_PC	Pathogenic	0.97
FATHMM_MKL	Pathogenic	0.99	D
MutationTaster	Benign	1.0	D;D;D;D;D
GERP RS		5.9

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.93
SpliceAI score (max)		0.98		Details are displayed if max score is > 0.2
DS_AG_spliceai		0.39		Position offset: 41
DS_AL_spliceai		0.98		Position offset: 2

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

Publications

LitVar

Other links and lift over

dbSNP: rs80356555; hg19: chr5-82832824;