rs747058298

Positions:

• chr1-21855389-C-A
• chr1-21855389-C-T

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 3P and 0B. PM2 PP2

The NM_005529.7(HSPG2):​c.5912G>T​(p.Arg1971Leu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000342 in 1,460,524 control chromosomes in the GnomAD database, with no homozygous occurrence. 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. R1971H) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000034 (0 hom.)
• Consequence: HSPG2 NM_005529.7 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 1.74

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 3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• 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.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
HSPG2	NM_005529.7	c.5912G>T	p.Arg1971Leu	missense_variant	47/97	ENST00000374695.8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
HSPG2	ENST00000374695.8	c.5912G>T	p.Arg1971Leu	missense_variant	47/97	1	NM_005529.7	P1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD3 exomes AF: 0.00000404 AC: 1 AN: 247728 Hom.: 0 AF XY: 0.00000744 AC XY: 1 AN XY: 134380

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: 0.00000893

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000342 AC: 5 AN: 1460524 Hom.: 0 Cov.: 32 AF XY: 0.00000275 AC XY: 2 AN XY: 726516

Gnomad4 AFR exome AF: 0.0000299

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: 0.00000360

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

Alfa AF: 0.0000178 Hom.: 0

Bravo AF: 0.00000378

ExAC AF: 0.00000824 AC: 1

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Jun 11, 2022

In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may create or strengthen a splice site. Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be tolerated. This variant has not been reported in the literature in individuals affected with HSPG2-related conditions. The frequency data for this variant in the population databases is considered unreliable, as metrics indicate poor data quality at this position in the gnomAD database. This sequence change replaces arginine, which is basic and polar, with leucine, which is neutral and non-polar, at codon 1971 of the HSPG2 protein (p.Arg1971Leu). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.17
BayesDel_addAF	Benign	-0.18	T
BayesDel_noAF	Benign	-0.49
CADD	Benign	23
DANN	Uncertain	0.99
DEOGEN2	Uncertain	0.65	D
Eigen	Benign	-0.31
Eigen_PC	Benign	-0.25
FATHMM_MKL	Benign	0.75	D
LIST_S2	Uncertain	0.87	D
M_CAP	Benign	0.0094	T
MetaRNN	Uncertain	0.69	D
MetaSVM	Benign	-1.0	T
MutationAssessor	Benign	0.71	N
MutationTaster	Benign	0.62	N
PrimateAI	Benign	0.34	T
PROVEAN	Uncertain	-3.1	D
REVEL	Benign	0.076
Sift	Benign	0.29	T
Sift4G	Uncertain	0.044	D
Polyphen		0.41	B
Vest4		0.55
MutPred		0.63		Loss of MoRF binding (P = 0.0095);
MVP		0.30
MPC		0.37
ClinPred		0.34	T
GERP RS		1.6
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.18
gMVP		0.40

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.42		Details are displayed if max score is > 0.2
DS_AG_spliceai		0.42		Position offset: -22

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

Publications

LitVar

Other links and lift over

dbSNP: rs747058298; hg19: chr1-22181882;