rs137904249

Positions:

• chr1-21876613-C-A
• chr1-21876613-C-T

Variant summary

Our verdict is Uncertain significance. Variant got 5 ACMG points: 5P and 0B. PP2 PP3_Strong

The ENST00000374695.8(HSPG2):​c.2725G>T​(p.Gly909Cys) variant causes a missense change. The variant allele was found at a frequency of 0.0000116 in 1,461,884 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 Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. G909S) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.000012 (0 hom.)
• Consequence: HSPG2 ENST00000374695.8 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 5.58

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 Uncertain_significance. Variant got 5 ACMG points.

• PP2: Missense variant in gene, where missense usually causes diseases (based on misZ statistic), HSPG2. . Gene score misZ 1.1367 (greater than the threshold 3.09). Trascript score misZ 3.3999 (greater than threshold 3.09). GenCC has associacion of gene with Silverman-Handmaker type dyssegmental dysplasia, Schwartz-Jampel syndrome type 1, Schwartz-Jampel syndrome.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.99

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
HSPG2	NM_005529.7	c.2725G>T	p.Gly909Cys	missense_variant	22/97	ENST00000374695.8	NP_005520.4

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
HSPG2	ENST00000374695.8	c.2725G>T	p.Gly909Cys	missense_variant	22/97	1	NM_005529.7	ENSP00000363827	P1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD3 exomes AF: 0.00000398 AC: 1 AN: 251378 Hom.: 0 AF XY: 0.00000736 AC XY: 1 AN XY: 135892

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: 0.0000116 AC: 17 AN: 1461884 Hom.: 0 Cov.: 33 AF XY: 0.00000825 AC XY: 6 AN XY: 727246

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: 0.0000153

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

Bravo AF: 0.00000378

EpiCase AF: 0.0000545

EpiControl AF: 0.00

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Inborn genetic diseases Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Apr 17, 2024

The c.2725G>T (p.G909C) alteration is located in exon 21 (coding exon 21) of the HSPG2 gene. This alteration results from a G to T substitution at nucleotide position 2725, causing the glycine (G) at amino acid position 909 to be replaced by a cysteine (C). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.80
BayesDel_addAF	Pathogenic	0.31	D
BayesDel_noAF	Pathogenic	0.21
CADD	Uncertain	26
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.85	D
Eigen	Uncertain	0.49
Eigen_PC	Uncertain	0.29
FATHMM_MKL	Benign	0.75	D
LIST_S2	Uncertain	0.91	D
M_CAP	Uncertain	0.085	D
MetaRNN	Pathogenic	0.99	D
MetaSVM	Uncertain	0.59	D
MutationAssessor	Pathogenic	4.3	H
MutationTaster	Benign	1.0	D
PrimateAI	Uncertain	0.54	T
PROVEAN	Pathogenic	-5.8	D
REVEL	Uncertain	0.55
Sift	Uncertain	0.0020	D
Sift4G	Pathogenic	0.0010	D
Polyphen		1.0	D
Vest4		0.89
MutPred		0.93		Loss of disorder (P = 0.2108);
MVP		0.81
MPC		0.81
ClinPred		1.0	D
GERP RS		5.0
Varity_R		0.63
gMVP		0.89

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.11		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: rs137904249; hg19: chr1-22203106;