chr17-47286394-A-G

Position:

• chr17-47286394-A-G

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PP4_Moderate PP3 PM2_Supporting PM3

This summary comes from the ClinGen Evidence Repository: The c.749A>G variant in ITGB3 is a missense variant predicted to cause substitution of aspartic acid by glycine at amino acid 250. The variant has been reported in at least one patient (Glanzmann Patient, "HEMOSTAZA SKOZIKLINIČNE PRIMERE" August 2022) who displayed mucocutaneous bleeding and impaired aggregation with all agonists except ristocetin, which is highly specific for Glanzmann thrombasthenia (PP4_moderate). This individual is compound heterozygous for this variant and pathogenic variant c.1699C>T (p.Gln567Ter) (PM3). The variant is absent from gnomAD (PM2_supporting). The computational predictor REVEL gives a score of 0.988, which is above the ClinGen PD VCEP PP3 threshold of >0.7 and predicts a damaging effect on ITGB3 function. In summary, this variant meets the criteria to be classified as likely pathogenic for autosomal recessive Glanzmann Thrombasthenia based on the ACMG/AMP criteria applied, as specified by the ClinGen PD VCEP: PM2_Supporting, PP3, PP4_moderate, and PM3. (VCEP specifications version 2) LINK:https://erepo.genome.network/evrepo/ui/classification/CA16043530/MONDO:0100326/011

• Frequency: Genomes: not found (cov: 32)
• Consequence: ITGB3 NM_000212.3 missense
• Clinical Significance: Likely pathogenic reviewed by expert panel P:3
• Conservation: PhyloP100: 9.32

Genes affected

ITGB3 (HGNC:6156): (integrin subunit beta 3) The ITGB3 protein product is the integrin beta chain beta 3. Integrins are integral cell-surface proteins composed of an alpha chain and a beta chain. A given chain may combine with multiple partners resulting in different integrins. Integrin beta 3 is found along with the alpha IIb chain in platelets. Integrins are known to participate in cell adhesion as well as cell-surface mediated signalling. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Likely_pathogenic. Variant got 6 ACMG points.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
ITGB3	NM_000212.3	c.749A>G	p.Asp250Gly	missense_variant	5/15	ENST00000559488.7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
ITGB3	ENST00000559488.7	c.749A>G	p.Asp250Gly	missense_variant	5/15	1	NM_000212.3	P1
ITGB3	ENST00000571680.1	c.749A>G	p.Asp250Gly	missense_variant	5/9	1
ITGB3	ENST00000696963.1	c.749A>G	p.Asp250Gly	missense_variant	5/14

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 32

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:3

Revision: reviewed by expert panel

Submissions by phenotype

Glanzmann thrombasthenia Pathogenic:1

Likely pathogenic, reviewed by expert panel

curation

ClinGen Platelet Disorders Variant Curation Expert Panel, ClinGen

Apr 06, 2023

The c.749A>G variant in ITGB3 is a missense variant predicted to cause substitution of aspartic acid by glycine at amino acid 250. The variant has been reported in at least one patient (Glanzmann Patient, "HEMOSTAZA SKOZI KLINIČNE PRIMERE" August 2022) who displayed mucocutaneous bleeding and impaired aggregation with all agonists except ristocetin, which is highly specific for Glanzmann thrombasthenia (PP4_moderate). This individual is compound heterozygous for this variant and pathogenic variant c.1699C>T (p.Gln567Ter) (PM3). The variant is absent from gnomAD (PM2_supporting). The computational predictor REVEL gives a score of 0.988, which is above the ClinGen PD VCEP PP3 threshold of >0.7 and predicts a damaging effect on ITGB3 function. In summary, this variant meets the criteria to be classified as likely pathogenic for autosomal recessive Glanzmann Thrombasthenia based on the ACMG/AMP criteria applied, as specified by the ClinGen PD VCEP: PM2_Supporting, PP3, PP4_moderate, and PM3. (VCEP specifications version 2) -

Prolonged bleeding time;C1458140:Abnormal bleeding Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Centre for Mendelian Genomics, University Medical Centre Ljubljana

Nov 06, 2015

- -

Platelet-type bleeding disorder 16 Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Centre for Mendelian Genomics, University Medical Centre Ljubljana

Jan 01, 2016

This variant was classified as: Likely pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.99
BayesDel_addAF	Pathogenic	0.57	D
BayesDel_noAF	Pathogenic	0.58
CADD	Pathogenic	30
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.98	D;.
Eigen	Pathogenic	0.96
Eigen_PC	Pathogenic	0.86
FATHMM_MKL	Uncertain	0.95	D
LIST_S2	Pathogenic	0.99	D;D
M_CAP	Pathogenic	0.63	D
MetaRNN	Pathogenic	0.99	D;D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Pathogenic	3.9	H;.
MutationTaster	Benign	1.0	D;D;D;D
PrimateAI	Uncertain	0.74	T
PROVEAN	Pathogenic	-6.8	D;.
Sift	Uncertain	0.0010	D;.
Sift4G	Pathogenic	0.0	D;D
Polyphen		1.0	D;.
Vest4		0.96
MutPred		0.94		Gain of catalytic residue at D250 (P = 0.0195);Gain of catalytic residue at D250 (P = 0.0195);
MVP		0.99
MPC		1.4
ClinPred		1.0	D
GERP RS		5.0
Varity_R		0.95
gMVP		0.96

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: rs1057518838; hg19: chr17-45363760;