chrX-133753912-G-A

Variant names:

• chrX-133753912-G-A
• rs201344338
• NM_004484.4:c.602C>T

Variant summary

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

The NM_004484.4(GPC3):​c.602C>T​(p.Ala201Val) variant causes a missense change. The variant was absent in control chromosomes in GnomAD project. 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. A201G) has been classified 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: 5.50
• Publications: 1 publications found

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]

GPC3 Gene-Disease associations (from GenCC):

• Simpson-Golabi-Behmel syndrome

  Inheritance: XL Classification: DEFINITIVE, SUPPORTIVE Submitted by: Orphanet, ClinGen
• Simpson-Golabi-Behmel syndrome type 1

  Inheritance: XL Classification: DEFINITIVE, STRONG Submitted by: G2P, Labcorp Genetics (formerly Invitae), Ambry Genetics

ACMG classification

Our verdict: Uncertain_significance. The variant received 2 ACMG points.

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

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
GPC3	NM_004484.4	c.602C>T	p.Ala201Val	missense_variant	Exon 3 of 8	ENST00000370818.8	NP_004475.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
GPC3	ENST00000370818.8	c.602C>T	p.Ala201Val	missense_variant	Exon 3 of 8	1	NM_004484.4	ENSP00000359854.3

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

Feb 27, 2019

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces alanine with valine at codon 201 of the GPC3 protein (p.Ala201Val). The alanine residue is highly conserved and there is a small physicochemical difference between alanine and valine. This variant is not present in population databases (ExAC no frequency). This variant has not been reported in the literature in individuals with GPC3-related conditions. Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Tolerated"; PolyPhen-2: "Probably Damaging"; Align-GVGD: "Class C0"). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may create or strengthen a splice site, but this prediction has not been confirmed by published transcriptional studies. 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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.25
BayesDel_addAF	Benign	-0.13	T
BayesDel_noAF	Benign	-0.42
CADD	Uncertain	26
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.48	T;.;.
FATHMM_MKL	Pathogenic	0.97	D
LIST_S2	Uncertain	0.89	D;D;D
M_CAP	Pathogenic	0.42	D
MetaRNN	Uncertain	0.55	D;D;D
MetaSVM	Benign	-0.69	T
MutationAssessor	Benign	1.9	L;L;.
PhyloP100		5.5
PrimateAI	Uncertain	0.53	T
PROVEAN	Uncertain	-2.6	D;D;.
REVEL	Benign	0.22
Sift	Benign	0.064	T;T;.
Sift4G	Uncertain	0.049	D;D;T
Polyphen		0.60	P;.;.
Vest4		0.21
MutPred		0.77		Gain of MoRF binding (P = 0.085);Gain of MoRF binding (P = 0.085);.;
MVP		0.40
MPC		0.54
ClinPred		0.95	D
GERP RS		5.5
PromoterAI		-0.0088	Neutral
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.66
gMVP		0.76
Mutation Taster		=82/18	polymorphism

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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: rs201344338; hg19: chrX-132887939;