17-47283410-CTG-C

Position:

• chr17-47283410-CTG-C

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The NM_000212.3(ITGB3):​c.225_226del​(p.Ala76ProfsTer10) variant causes a frameshift change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000205 in 1,461,888 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Pathogenic (★★★). Variant results in nonsense mediated mRNA decay.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000021 (0 hom.)
• Consequence: ITGB3 NM_000212.3 frameshift
• Clinical Significance: Pathogenic reviewed by expert panel P:2
• Conservation: PhyloP100: 10.0

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 18 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 17-47283410-CTG-C is Pathogenic according to our data. Variant chr17-47283410-CTG-C is described in ClinVar as [Pathogenic]. Clinvar id is 1330313.Status of the report is reviewed_by_expert_panel, 3 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
ITGB3	NM_000212.3	c.225_226del	p.Ala76ProfsTer10	frameshift_variant	3/15	ENST00000559488.7	NP_000203.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
ITGB3	ENST00000559488.7	c.225_226del	p.Ala76ProfsTer10	frameshift_variant	3/15	1	NM_000212.3	ENSP00000452786	P1
ITGB3	ENST00000571680.1	c.225_226del	p.Ala76ProfsTer10	frameshift_variant	3/9	1		ENSP00000461626
ITGB3	ENST00000696963.1	c.225_226del	p.Ala76ProfsTer10	frameshift_variant	3/14			ENSP00000513002

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000795 AC: 2 AN: 251426 Hom.: 0 AF XY: 0.0000147 AC XY: 2 AN XY: 135890

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.000109

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000205 AC: 3 AN: 1461888 Hom.: 0 AF XY: 0.00000275 AC XY: 2 AN XY: 727242

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.0000504

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:2

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

Nov 09, 2021

NM_000212.3(ITGB3):c.225_226del (p.Ala76ProfsTer10) in exon 3 of ITGB3 is a frameshift variant predicted to cause a premature stop codon in biologically-relevant-exon 3/15 and is predicted to lead to nonsense mediated decay (PVS1). GT7 of PMID: 32237906 displayed mucocutaneous bleeding and impaired aggregation with all agonists except ristocetin, which is highly specific for Glanzmann thrombasthenia (PP4_moderate). Additionally, β3 surface expression was reduced to 0.3%, as measured by flow cytometry. GT7 (PMID: 32237906) is compound heterozygous for c.225_226del and Arg242Ter (classified Pathogenic by the PD-VCEP; PM3_supporting). The highest population minor allele frequency in gnomAD v2.1.1 is 0.0001087 (2/18394 alleles) in the East Asian population, which is lower than the ClinGen PD VCEP threshold (<0.0001; 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, PM2_supporting, PM3_supporting. (VCEP specifications version 2; date of approval 11/04/2021) -

not provided Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

May 20, 2023

This sequence change creates a premature translational stop signal (p.Ala76Profs*10) in the ITGB3 gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in ITGB3 are known to be pathogenic (PMID: 21917754). This variant is present in population databases (no rsID available, gnomAD 0.01%). This variant has not been reported in the literature in individuals affected with ITGB3-related conditions. For these reasons, this variant has been classified as Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.14		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: rs1438135616; hg19: chr17-45360776;