1-21840020-G-A

Position:

• chr1-21840020-G-A

Variant summary

Our verdict is Benign. Variant got -20 ACMG points: 0P and 20B. BP4_Strong BP6_Very_Strong BS1 BS2

The NM_005529.7(HSPG2):​c.9514-3C>T variant causes a splice region, splice polypyrimidine tract, intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000499 in 1,614,092 control chromosomes in the GnomAD database, including 4 homozygotes. In-silico tool predicts a benign outcome for this variant. 1/1 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Likely benign (★★).

• Frequency:
  • Genomes: 𝑓 0.0027 (2 hom., cov: 32)
  • Exomes 𝑓: 0.00027 (2 hom.)
• Consequence: HSPG2 NM_005529.7 splice_region, splice_polypyrimidine_tract, intron
• Clinical Significance: Benign/Likely benign criteria provided, multiple submitters, no conflicts B:6
• Conservation: PhyloP100: 3.58

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]

ACMG classification

Verdict is Benign. Variant got -20 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.64).
• BP6: Variant 1-21840020-G-A is Benign according to our data. Variant chr1-21840020-G-A is described in ClinVar as [Likely_benign]. Clinvar id is 447568.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
• BS1: Variant frequency is greater than expected in population afr. gnomad4 allele frequency = 0.00266 (406/152366) while in subpopulation AFR AF= 0.00895 (372/41586). AF 95% confidence interval is 0.0082. There are 2 homozygotes in gnomad4. There are 168 alleles in male gnomad4 subpopulation. Median coverage is 32. This position pass quality control queck.
• BS2: High Homozygotes in GnomAd4 at 2 AD,AR gene

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
HSPG2	NM_005529.7	c.9514-3C>T		splice_region_variant, splice_polypyrimidine_tract_variant, intron_variant		ENST00000374695.8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
HSPG2	ENST00000374695.8	c.9514-3C>T		splice_region_variant, splice_polypyrimidine_tract_variant, intron_variant		1	NM_005529.7	P1

Frequencies

GnomAD3 genomes AF: 0.00267 AC: 406 AN: 152248 Hom.: 2 Cov.: 32

Gnomad AFR AF: 0.00897

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00157

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000441

Gnomad OTH AF: 0.00335

GnomAD3 exomes AF: 0.000749 AC: 188 AN: 251168 Hom.: 2 AF XY: 0.000567 AC XY: 77 AN XY: 135744

Gnomad AFR exome AF: 0.0103

Gnomad AMR exome AF: 0.000463

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: 0.00000881

Gnomad OTH exome AF: 0.000489

GnomAD4 exome AF: 0.000274 AC: 400 AN: 1461726 Hom.: 2 Cov.: 32 AF XY: 0.000252 AC XY: 183 AN XY: 727184

Gnomad4 AFR exome AF: 0.00935

Gnomad4 AMR exome AF: 0.000693

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.0000232

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000360

Gnomad4 OTH exome AF: 0.000778

GnomAD4 genome AF: 0.00266 AC: 406 AN: 152366 Hom.: 2 Cov.: 32 AF XY: 0.00225 AC XY: 168 AN XY: 74512

Gnomad4 AFR AF: 0.00895

Gnomad4 AMR AF: 0.00157

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000441

Gnomad4 OTH AF: 0.00331

Alfa AF: 0.00176 Hom.: 1

Bravo AF: 0.00312

Asia WGS AF: 0.000577 AC: 2 AN: 3478

ClinVar

Significance: Benign/Likely benign

Submissions summary: Benign:6

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Benign:3

Likely benign, criteria provided, single submitter	clinical testing	GeneDx	Jul 22, 2021	- -
Benign, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Dec 19, 2023	- -
Likely benign, criteria provided, single submitter	clinical testing	ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories	Jan 29, 2021	- -

not specified Benign:2

Benign, criteria provided, single submitter	clinical testing	Athena Diagnostics	Nov 08, 2016	- -
Benign, criteria provided, single submitter	clinical testing	Eurofins Ntd Llc (ga)	Nov 22, 2016	- -

Connective tissue disorder Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Genome Diagnostics Laboratory, The Hospital for Sick Children

Sep 30, 2020

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.64
CADD	Benign	8.5
DANN	Benign	0.48

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: rs114851424; hg19: chr1-22166513;