1-21852139-G-C

Variant names:

• chr1-21852139-G-C
• rs151177187
• NM_005529.7:c.6819C>G

Variant summary

Our verdict is Uncertain significance. The variant received 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_005529.7(HSPG2):​c.6819C>G​(p.His2273Gln) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000205 in 1,461,462 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 14/22 in silico tools predict a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. H2273Y) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000021 (0 hom.)
• Consequence: HSPG2 NM_005529.7 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: -4.00
• Publications: 0 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 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.21761283).

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_005529.7. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	HSPG2	NM_005529.7	MANE Select	c.6819C>G	p.His2273Gln	missense	Exon 53 of 97	NP_005520.4
	HSPG2	NM_001291860.2		c.6822C>G	p.His2274Gln	missense	Exon 53 of 97	NP_001278789.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	HSPG2	ENST00000374695.8	TSL:1 MANE Select	c.6819C>G	p.His2273Gln	missense	Exon 53 of 97	ENSP00000363827.3
	HSPG2	ENST00000493940.2	TSL:5	n.305-549C>G		intron	N/A

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 0.00000205 AC: 3 AN: 1461462 Hom.: 0 Cov.: 32 AF XY: 0.00000275 AC XY: 2 AN XY: 727052

African (AFR) AF: 0.00 AC: 0 AN: 33478

American (AMR) AF: 0.00 AC: 0 AN: 44716

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

East Asian (EAS) AF: 0.00 AC: 0 AN: 39700

South Asian (SAS) AF: 0.00 AC: 0 AN: 86242

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53064

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5766

European-Non Finnish (NFE) AF: 0.00000180 AC: 2 AN: 1111974

Other (OTH) AF: 0.0000166 AC: 1 AN: 60386

GnomAD4 genome Cov.: 33

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.13
BayesDel_addAF	Benign	-0.0099	T
BayesDel_noAF	Benign	-0.25
CADD	Benign	0.063
DANN	Benign	0.96
DEOGEN2	Benign	0.11	T
Eigen	Benign	-1.6
Eigen_PC	Benign	-1.5
FATHMM_MKL	Benign	0.091	N
LIST_S2	Benign	0.64	T
M_CAP	Benign	0.014	T
MetaRNN	Benign	0.22	T
MetaSVM	Benign	-1.0	T
MutationAssessor	Benign	-0.48	N
PhyloP100		-4.0
PrimateAI	Uncertain	0.58	T
PROVEAN	Benign	-2.2	N
REVEL	Uncertain	0.33
Sift	Benign	0.49	T
Sift4G	Benign	0.66	T
Polyphen		0.0010	B
Vest4		0.58
MutPred		0.40		Loss of catalytic residue at Q2275 (P = 0.074)
MVP		0.18
MPC		0.21
ClinPred		0.087	T
GERP RS		-4.9
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.056
gMVP		0.19
Mutation Taster		=93/7	polymorphism

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

Other links and lift over

dbSNP: rs151177187; hg19: chr1-22178632;