17-44372392-AG-A

Variant names:

• chr17-44372392-AG-A
• NM_000419.5:c.3091delC

Variant summary

Our verdict is Likely pathogenic. Variant got 9 ACMG points: 9P and 0B. PM2_Supporting PP4_Strong PM4 PM3

This summary comes from the ClinGen Evidence Repository: The NM_000419.5(ITGA2B):c.3091del variant causes a frameshift and subsequent stop loss, Leu1031TrpfsTer97. This results in the addition of 90 amino acids to the ITGA2B protein, beyond the cytoplasmic domain (PM4). This variant is absent from gnomAD v4.1 (PM2_Supporting). At least one patient (Patient GT10 in PMID:25373348) 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 severely reduced, as measured by flow cytometry (PP4_strong). GT10 of PMID:25373348 is compound heterozygous for the paternal c.1210+105A>G (classified Likely Pathogenic by the PD-EP) and the maternal c.3091delC variants (PM3). In summary this variant meets 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: PP4_strong, PM2_supporting, PM3, PM4. (VCEP specifications version 2) LINK:https://erepo.genome.network/evrepo/ui/classification/CA915940322/MONDO:0100326/011

• Frequency: Genomes: not found (cov: 31)
• Consequence: ITGA2B NM_000419.5 frameshift
• Clinical Significance: Likely pathogenic reviewed by expert panel P:1
• Conservation: PhyloP100: 1.06

Genes affected

ITGA2B (HGNC:6138): (integrin subunit alpha 2b) This gene encodes a member of the integrin alpha chain family of proteins. The encoded preproprotein is proteolytically processed to generate light and heavy chains that associate through disulfide linkages to form a subunit of the alpha-IIb/beta-3 integrin cell adhesion receptor. This receptor plays a crucial role in the blood coagulation system, by mediating platelet aggregation. Mutations in this gene are associated with platelet-type bleeding disorders, which are characterized by a failure of platelet aggregation, including Glanzmann thrombasthenia. [provided by RefSeq, Jan 2016]

ACMG classification

Verdict is Likely_pathogenic. Variant got 9 ACMG points.

• PM2: For more information check the summary or visit ClinGen Evidence Repository.
• PM3: For more information check the summary or visit ClinGen Evidence Repository.
• PM4: For more information check the summary or visit ClinGen Evidence Repository.
• PP4: For more information check the summary or visit ClinGen Evidence Repository.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
ITGA2B	NM_000419.5	c.3091delC	p.Leu1031TrpfsTer70	frameshift_variant	Exon 30 of 30	ENST00000262407.6	NP_000410.2
ITGA2B	XM_011524749.2	c.3142delC	p.Leu1048TrpfsTer70	frameshift_variant	Exon 29 of 29		XP_011523051.2
ITGA2B	XM_011524750.2	c.3127delC	p.Leu1043TrpfsTer70	frameshift_variant	Exon 29 of 29		XP_011523052.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
ITGA2B	ENST00000262407.6	c.3091delC	p.Leu1031TrpfsTer70	frameshift_variant	Exon 30 of 30	1	NM_000419.5	ENSP00000262407.5
ITGA2B	ENST00000648408.1	c.2404delC	p.Leu802fs	frameshift_variant	Exon 25 of 25			ENSP00000498119.1
ITGA2B	ENST00000587295.5	c.283delC	p.Leu95fs	frameshift_variant	Exon 3 of 3	3		ENSP00000467269.1

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome Cov.: 30

GnomAD4 genome Cov.: 31

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:1

Revision: reviewed by expert panel

Submissions by phenotype

Glanzmann thrombasthenia Pathogenic:1

Dec 17, 2024

ClinGen Platelet Disorders Variant Curation Expert Panel, ClinGen

Significance: Likely pathogenic

Review Status: reviewed by expert panel

Collection Method: curation

The NM_000419.5(ITGA2B):c.3091del variant causes a frameshift and subsequent stop loss, Leu1031TrpfsTer97. This results in the addition of 90 amino acids to the ITGA2B protein, beyond the cytoplasmic domain (PM4). This variant is absent from gnomAD v4.1 (PM2_Supporting). At least one patient (Patient GT10 in PMID:25373348) 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 severely reduced, as measured by flow cytometry (PP4_strong). GT10 of PMID: 25373348 is compound heterozygous for the paternal c.1210+105A>G (classified Likely Pathogenic by the PD-EP) and the maternal c.3091delC variants (PM3). In summary this variant meets 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: PP4_strong, PM2_supporting, PM3, PM4. (VCEP specifications version 2) -

Computational scores

Source: dbNSFP v4.3

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

No publications associated with this variant yet.

Other links and lift over

hg19: chr17-42449760;