1-21864095-C-T

Variant names:

• chr1-21864095-C-T
• rs886039909
• NM_005529.7:c.4740+5G>A

Variant summary

Our verdict is Uncertain significance. The variant received 5 ACMG points: 5P and 0B. PM2 PP3 PP5_Moderate

The NM_005529.7(HSPG2):​c.4740+5G>A variant causes a splice region, intron change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. 1/1 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Likely pathogenic (★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0 (0 hom.)
  • Failed GnomAD Quality Control
• Consequence: HSPG2 NM_005529.7 splice_region, intron
• Clinical Significance: Likely pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 6.40
• Publications: 3 publications found

Genes affected

HSPG2 (HGNC:5273): (heparan sulfate proteoglycan 2) This gene encodes the perlecan protein, which consists of a core protein to which three long chains of glycosaminoglycans (heparan sulfate or chondroitin sulfate) are attached. The perlecan protein is a large multidomain proteoglycan that binds to and cross-links many extracellular matrix components and cell-surface molecules. It has been shown that this protein interacts with laminin, prolargin, collagen type IV, FGFBP1, FBLN2, FGF7 and transthyretin, etc., and it plays essential roles in multiple biological activities. Perlecan is a key component of the vascular extracellular matrix, where it helps to maintain the endothelial barrier function. It is a potent inhibitor of smooth muscle cell proliferation and is thus thought to help maintain vascular homeostasis. It can also promote growth factor (e.g., FGF2) activity and thus stimulate endothelial growth and re-generation. It is a major component of basement membranes, where it is involved in the stabilization of other molecules as well as being involved with glomerular permeability to macromolecules and cell adhesion. Mutations in this gene cause Schwartz-Jampel syndrome type 1, Silverman-Handmaker type of dyssegmental dysplasia, and tardive dyskinesia. Alternative splicing of this gene results in multiple transcript variants. [provided by RefSeq, May 2014]

HSPG2 Gene-Disease associations (from GenCC):

• Schwartz-Jampel syndrome type 1

  Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: ClinGen, Labcorp Genetics (formerly Invitae), G2P
• Silverman-Handmaker type dyssegmental dysplasia

  Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Orphanet, G2P, ClinGen, Labcorp Genetics (formerly Invitae)
• Schwartz-Jampel syndrome

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Uncertain_significance. The variant received 5 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: Splicing predictors support a deleterious effect. Scorers claiming Pathogenic: max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.
• PP5: Variant 1-21864095-C-T is Pathogenic according to our data. Variant chr1-21864095-C-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 266114.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
HSPG2	NM_005529.7	c.4740+5G>A		splice_region_variant, intron_variant	Intron 37 of 96	ENST00000374695.8	NP_005520.4

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
HSPG2	ENST00000374695.8	c.4740+5G>A		splice_region_variant, intron_variant	Intron 37 of 96	1	NM_005529.7	ENSP00000363827.3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Data not reliable, filtered out with message: AC0 AF: 0.00 AC: 0 AN: 1397920 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 689694

African (AFR) AF: 0.00 AC: 0 AN: 31620

American (AMR) AF: 0.00 AC: 0 AN: 35902

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 25182

East Asian (EAS) AF: 0.00 AC: 0 AN: 35836

South Asian (SAS) AF: 0.00 AC: 0 AN: 79232

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 49106

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 4752

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1078366

Other (OTH) AF: 0.00 AC: 0 AN: 57924

GnomAD4 genome Cov.: 32

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

Schwartz-Jampel syndrome Pathogenic:1

Jan 01, 2015

Diagnostics Division, CENTRE FOR DNA FINGERPRINTING AND DIAGNOSTICS

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: research

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.29
CADD	Uncertain	25
DANN	Uncertain	0.97
PhyloP100		6.4
Mutation Taster		=11/89	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.80		Details are displayed if max score is > 0.2
DS_DG_spliceai		0.71		Position offset: -24
DS_DL_spliceai		0.80		Position offset: 5

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

Other links and lift over

dbSNP: rs886039909; hg19: chr1-22190588;