chr1-21887500-C-A

Position:

• chr1-21887500-C-A

Variant summary

Our verdict is Uncertain significance. Variant got 1 ACMG points: 3P and 2B. PM2 PP2 BP4_Moderate

The NM_005529.7(HSPG2):​c.878G>T​(p.Arg293Leu) 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 1,461,682 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 14/21 in silico tools predict a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000034 (0 hom.)
• Consequence: HSPG2 NM_005529.7 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: -0.600

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 1 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.
• BP4: Computational evidence support a benign effect (MetaRNN=0.17201716).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
HSPG2	NM_005529.7	c.878G>T	p.Arg293Leu	missense_variant	8/97	ENST00000374695.8	NP_005520.4

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
HSPG2	ENST00000374695.8	c.878G>T	p.Arg293Leu	missense_variant	8/97	1	NM_005529.7	ENSP00000363827	P1
HSPG2	ENST00000374673.4	c.686G>T	p.Arg229Leu	missense_variant	6/7	3		ENSP00000497688
HSPG2	ENST00000412328.5	n.646G>T		non_coding_transcript_exon_variant	5/6	2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000342 AC: 5 AN: 1461682 Hom.: 0 Cov.: 34 AF XY: 0.00000275 AC XY: 2 AN XY: 727150

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: 0.0000116

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000180

Gnomad4 OTH exome AF: 0.0000166

GnomAD4 genome Cov.: 32

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.088
BayesDel_addAF	Benign	-0.27	T
BayesDel_noAF	Benign	-0.13
CADD	Benign	4.7
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.46	T
Eigen	Benign	-0.88
Eigen_PC	Benign	-0.88
FATHMM_MKL	Benign	0.27	N
LIST_S2	Benign	0.79	T
M_CAP	Benign	0.016	T
MetaRNN	Benign	0.17	T
MetaSVM	Benign	-0.31	T
MutationAssessor	Benign	0.79	N
MutationTaster	Benign	1.0	N
PrimateAI	Benign	0.27	T
PROVEAN	Benign	-2.2	N
REVEL	Uncertain	0.40
Sift	Benign	0.38	T
Sift4G	Benign	0.81	T
Polyphen		0.10	B
Vest4		0.21
MutPred		0.61		Gain of catalytic residue at R293 (P = 0.0553);
MVP		0.65
MPC		0.25
ClinPred		0.20	T
GERP RS		-1.9
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.053
gMVP		0.21

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.18		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: rs139873789; hg19: chr1-22213993;