chr17-47299316-C-T

Position:

• chr17-47299316-C-T

Variant summary

Our verdict is Pathogenic. Variant got 11 ACMG points: 11P and 0B. PVS1 PP4_Moderate PM2_Supporting

This summary comes from the ClinGen Evidence Repository: The c.1699C>T (p.Gln567Ter) variant in exon 11 is a nonsense variant predicted to cause a premature stop codon in biologically-relevant-exon 11/15 and is predicted to lead to nonsense mediated decay in a gene in which loss-of-function is an established disease mechanism (PVS1). At least one patient (Glanzmann Patient, "HEMOSTAZA SKOZI KLINIČNE PRIMERE", August 2022) with this variant displayed mucocutaneous bleeding and impaired aggregation with all agonists except ristocetin, which is highly specific for Glanzmann thrombasthenia. Additionally, αIIbβ3 surface expression was reduced to 0% (<25%), as measured by flow cytometry (PP4_moderate). This individual is compound heterozygous for this variant and likely pathogenic variant c.749A>G (p.Asp250Gly). This variant is absent from gnomAD v2.1.1 (PM2_Supporting). In summary, this variant meets the criteria to be classified as Pathogenic for autosomal recessive Glanzmann Thrombasthenia based on the ACMG/AMP criteria applied, as specified by the ClinGen PD VCEP: PVS1, PP4_Moderate and PM2_Supporting (VCEP specifications version 2). LINK:https://erepo.genome.network/evrepo/ui/classification/CA16043531/MONDO:0100326/011

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: ITGB3 NM_000212.3 stop_gained
• Clinical Significance: Pathogenic reviewed by expert panel P:3
• Conservation: PhyloP100: 0.270

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 Pathogenic. Variant got 11 ACMG points.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
ITGB3	NM_000212.3	c.1699C>T	p.Gln567Ter	stop_gained	11/15	ENST00000559488.7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
ITGB3	ENST00000559488.7	c.1699C>T	p.Gln567Ter	stop_gained	11/15	1	NM_000212.3	P1
ITGB3	ENST00000696963.1	c.1699C>T	p.Gln567Ter	stop_gained	11/14

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461626 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 727130

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 8.99e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:3

Revision: reviewed by expert panel

Submissions by phenotype

Glanzmann thrombasthenia Pathogenic:1

Pathogenic, reviewed by expert panel

curation

ClinGen Platelet Disorders Variant Curation Expert Panel, ClinGen

Apr 06, 2023

The c.1699C>T (p.Gln567Ter) variant in exon 11 is a nonsense variant predicted to cause a premature stop codon in biologically-relevant-exon 11/15 and is predicted to lead to nonsense mediated decay in a gene in which loss-of-function is an established disease mechanism (PVS1). At least one patient (Glanzmann Patient, "HEMOSTAZA SKOZI KLINIČNE PRIMERE", August 2022) with this variant displayed mucocutaneous bleeding and impaired aggregation with all agonists except ristocetin, which is highly specific for Glanzmann thrombasthenia. Additionally, αIIbβ3 surface expression was reduced to 0% (<25%), as measured by flow cytometry (PP4_moderate). This individual is compound heterozygous for this variant and likely pathogenic variant c.749A>G (p.Asp250Gly). This variant is absent from gnomAD v2.1.1 (PM2_Supporting). In summary, this variant meets the criteria to be classified as Pathogenic for autosomal recessive Glanzmann Thrombasthenia based on the ACMG/AMP criteria applied, as specified by the ClinGen PD VCEP: PVS1, PP4_Moderate and PM2_Supporting (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
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Pathogenic	0.60
CADD	Pathogenic	39
DANN	Uncertain	1.0
Eigen	Pathogenic	0.74
Eigen_PC	Uncertain	0.58
FATHMM_MKL	Uncertain	0.80	D
MutationTaster	Benign	1.0	A;A;A
Vest4		0.93
GERP RS		5.5

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.060		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: rs1057518837; hg19: chr17-45376682;