rs1556297755

Positions:

• chrX-133753868-T-C

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_004484.4(GPC3):​c.646A>G​(p.Met216Val) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. 12/20 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: not found (cov: 23)
• Consequence: GPC3 NM_004484.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 3.05

Genes affected

GPC3 (HGNC:4451): (glypican 3) Cell surface heparan sulfate proteoglycans are composed of a membrane-associated protein core substituted with a variable number of heparan sulfate chains. Members of the glypican-related integral membrane proteoglycan family (GRIPS) contain a core protein anchored to the cytoplasmic membrane via a glycosyl phosphatidylinositol linkage. These proteins may play a role in the control of cell division and growth regulation. The protein encoded by this gene can bind to and inhibit the dipeptidyl peptidase activity of CD26, and it can induce apoptosis in certain cell types. Deletion mutations in this gene are associated with Simpson-Golabi-Behmel syndrome, also known as Simpson dysmorphia syndrome. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Sep 2009]

ACMG classification

Verdict is Uncertain_significance. Variant got 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.2426183).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
GPC3	NM_004484.4	c.646A>G	p.Met216Val	missense_variant	3/8	ENST00000370818.8	NP_004475.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
GPC3	ENST00000370818.8	c.646A>G	p.Met216Val	missense_variant	3/8	1	NM_004484.4	ENSP00000359854	P1

Frequencies

GnomAD3 genomes Cov.: 23

GnomAD4 exome Cov.: 33

GnomAD4 genome Cov.: 23

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Wilms tumor 1 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jul 19, 2023

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. Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is not expected to disrupt GPC3 protein function. ClinVar contains an entry for this variant (Variation ID: 543087). This variant has not been reported in the literature in individuals affected with GPC3-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces methionine, which is neutral and non-polar, with valine, which is neutral and non-polar, at codon 216 of the GPC3 protein (p.Met216Val). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.52
BayesDel_addAF	Benign	-0.14	T
BayesDel_noAF	Benign	-0.44
CADD	Benign	22
DANN	Benign	0.96
DEOGEN2	Benign	0.34	T;.;.
FATHMM_MKL	Uncertain	0.81	D
LIST_S2	Uncertain	0.90	D;T;D
M_CAP	Uncertain	0.092	D
MetaRNN	Benign	0.24	T;T;T
MetaSVM	Benign	-0.91	T
MutationAssessor	Benign	1.2	L;L;.
MutationTaster	Benign	0.84	D;D;D
PrimateAI	Uncertain	0.62	T
PROVEAN	Benign	-1.3	N;N;.
REVEL	Benign	0.097
Sift	Benign	0.46	T;T;.
Sift4G	Benign	0.26	T;T;T
Polyphen		0.024	B;.;.
Vest4		0.22
MutPred		0.60		Loss of methylation at K213 (P = 0.1247);Loss of methylation at K213 (P = 0.1247);.;
MVP		0.72
MPC		0.32
ClinPred		0.52	D
GERP RS		5.8
Varity_R		0.48
gMVP		0.76

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: rs1556297755; hg19: chrX-132887895; COSMIC: COSV100892953; COSMIC: COSV100892953;