rs76811038

Variant summary

Our verdict is Pathogenic. The variant received 10 ACMG points: 10P and 0B. PP4_StrongPP1PM2_SupportingPM3_Strong

This summary comes from the ClinGen Evidence Repository: The NM_000419.5(ITGA2B):c.1787T>C (p.Ile596Thr) missense variant has been reported in the homozygous state in at least 2 apparently unrelated individuals (PMID:22513797, 20020534) and in the compound heterozygous state in 4 individuals (PMID:9215749, 9734640, 34552732, 25373348). The second variants in these patients are c.3060+2T>C (classified Pathogenic by the PD-VCEP; without confirmation of trans phase), Glu355Lys (classified Pathogenic by the PD-VCEP; with confirmation of trans phase), c.2841+1G>T, and c.408G>C (latter two not considered here to avoid circularity) respectively (PM3_Strong). The proband from PMID:22513797 meets criteria for PP4_Strong including mucocutaneous bleeding; abnormal platelet aggregometry in response to at least 2 agonist and normal response to ristocetin; absent surface expression of GPIIb-IIIa on flow cytometry; and full sequencing of ITGA2B and ITGB3. It was found to co-segregate with disease in 1 additional family member (PP1). Ile596Thr is reported in gnomAD v4.0.0 at a frequency of 0.00008305 (98/1179968 alleles) in the non-Finnish European population, below the PM2_supporting threshold of <0.0001. In summary, this variant is classified Pathogenic for autosomal recessive Glanzmann thrombasthenia. GT-specific codes applied: PP4_Strong, PM2_Supporting, PM3_Strong, PP1. (PD-VCEP specifications version 2) LINK:https://erepo.genome.network/evrepo/ui/classification/CA115846/MONDO:0100326/011

Frequency

Genomes: 𝑓 0.000053 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000066 ( 0 hom. )

Consequence

ITGA2B
NM_000419.5 missense

Scores

9
7
3

Clinical Significance

Pathogenic reviewed by expert panel P:6

Conservation

PhyloP100: 6.13

Publications

10 publications found
Variant links:
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]
ITGA2B Gene-Disease associations (from GenCC):
  • platelet-type bleeding disorder 16
    Inheritance: AD Classification: DEFINITIVE, STRONG, MODERATE Submitted by: ClinGen, Ambry Genetics, Labcorp Genetics (formerly Invitae)
  • Glanzmann thrombasthenia
    Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen
  • Glanzmann's thrombasthenia
    Inheritance: AR Classification: DEFINITIVE, SUPPORTIVE Submitted by: Orphanet, Ambry Genetics
  • Glanzmann thrombasthenia 1
    Inheritance: AR Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae)
  • autosomal dominant macrothrombocytopenia
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Pathogenic. The variant received 10 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.
PP1
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
ITGA2BNM_000419.5 linkc.1787T>C p.Ile596Thr missense_variant Exon 18 of 30 ENST00000262407.6 NP_000410.2 P08514-1
ITGA2BXM_011524749.2 linkc.1940T>C p.Ile647Thr missense_variant Exon 18 of 29 XP_011523051.2 P08514
ITGA2BXM_011524750.2 linkc.1940T>C p.Ile647Thr missense_variant Exon 18 of 29 XP_011523052.2

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
ITGA2BENST00000262407.6 linkc.1787T>C p.Ile596Thr missense_variant Exon 18 of 30 1 NM_000419.5 ENSP00000262407.5 P08514-1
ITGA2BENST00000648408.1 linkc.1217T>C p.Ile406Thr missense_variant Exon 14 of 25 ENSP00000498119.1 A0A3B3IU79
ITGA2BENST00000592462.5 linkn.582T>C non_coding_transcript_exon_variant Exon 7 of 15 5

Frequencies

GnomAD3 genomes
AF:
0.0000527
AC:
8
AN:
151884
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.0000484
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.0000883
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000638
AC:
16
AN:
250706
AF XY:
0.0000442
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.0000462
Gnomad NFE exome
AF:
0.000133
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000657
AC:
96
AN:
1461712
Hom.:
0
Cov.:
33
AF XY:
0.0000605
AC XY:
44
AN XY:
727160
show subpopulations
African (AFR)
AF:
0.0000597
AC:
2
AN:
33480
American (AMR)
AF:
0.00
AC:
0
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39700
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86258
European-Finnish (FIN)
AF:
0.0000188
AC:
1
AN:
53246
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.0000827
AC:
92
AN:
1112008
Other (OTH)
AF:
0.0000166
AC:
1
AN:
60392
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.498
Heterozygous variant carriers
0
6
12
19
25
31
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
4
8
12
16
20
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
GnomAD4 genome
AF:
0.0000527
AC:
8
AN:
151884
Hom.:
0
Cov.:
32
AF XY:
0.0000270
AC XY:
2
AN XY:
74182
show subpopulations
African (AFR)
AF:
0.0000484
AC:
2
AN:
41350
American (AMR)
AF:
0.00
AC:
0
AN:
15256
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3464
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5138
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4816
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10598
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000883
AC:
6
AN:
67960
Other (OTH)
AF:
0.00
AC:
0
AN:
2076
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.519
Heterozygous variant carriers
0
1
1
2
2
3
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
Alfa
AF:
0.0000792
Hom.:
0
Bravo
AF:
0.0000642
ExAC
AF:
0.000107
AC:
13
EpiCase
AF:
0.000109
EpiControl
AF:
0.0000593

ClinVar

Significance: Pathogenic
Submissions summary: Pathogenic:6
Revision: reviewed by expert panel
LINK: link

Submissions by phenotype

Glanzmann thrombasthenia Pathogenic:2
Nov 17, 2023
ClinGen Platelet Disorders Variant Curation Expert Panel, ClinGen
Significance:Pathogenic
Review Status:reviewed by expert panel
Collection Method:curation

The NM_000419.5(ITGA2B):c.1787T>C (p.Ile596Thr) missense variant has been reported in the homozygous state in at least 2 apparently unrelated individuals (PMID: 22513797, 20020534) and in the compound heterozygous state in 4 individuals (PMID: 9215749, 9734640, 34552732, 25373348). The second variants in these patients are c.3060+2T>C (classified Pathogenic by the PD-VCEP; without confirmation of trans phase), Glu355Lys (classified Pathogenic by the PD-VCEP; with confirmation of trans phase), c.2841+1G>T, and c.408G>C (latter two not considered here to avoid circularity) respectively (PM3_Strong). The proband from PMID: 22513797 meets criteria for PP4_Strong including mucocutaneous bleeding; abnormal platelet aggregometry in response to at least 2 agonist and normal response to ristocetin; absent surface expression of GPIIb-IIIa on flow cytometry; and full sequencing of ITGA2B and ITGB3. It was found to co-segregate with disease in 1 additional family member (PP1). Ile596Thr is reported in gnomAD v4.0.0 at a frequency of 0.00008305 (98/1179968 alleles) in the non-Finnish European population, below the PM2_supporting threshold of <0.0001. In summary, this variant is classified Pathogenic for autosomal recessive Glanzmann thrombasthenia. GT-specific codes applied: PP4_Strong, PM2_Supporting, PM3_Strong, PP1. (PD-VCEP specifications version 2) -

Jul 04, 2022
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces isoleucine, which is neutral and non-polar, with threonine, which is neutral and polar, at codon 596 of the ITGA2B protein (p.Ile596Thr). This variant is present in population databases (rs76811038, gnomAD 0.01%). This missense change has been observed in individuals with clinical features of Glanzmann thrombasthenia (PMID: 9215749, 9734640, 20020534, 22513797, 25326637, 25373348). It has also been observed to segregate with disease in related individuals. ClinVar contains an entry for this variant (Variation ID: 2900). 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: "Deleterious"; PolyPhen-2: "Probably Damaging"; Align-GVGD: "Class C0"). For these reasons, this variant has been classified as Pathogenic. -

Glanzmann thrombasthenia 1 Pathogenic:2
Jun 02, 2023
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Variant summary: ITGA2B c.1787T>C (p.Ile596Thr) results in a non-conservative amino acid change located in the Integrin alpha-2 domain (IPR013649) of the encoded protein sequence. Five of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 6.4e-05 in 250706 control chromosomes (gnomAD). c.1787T>C has been reported in the literature as a biallelic genotype in individuals affected with Glanzmann thrombasthenia 1 (e.g. French_1997, Ruan_1998, Jallu_2010) and in one potential compound heterozygote (e.g. Lee_2014). These data indicate that the variant is likely to be associated with disease. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. The following publications have been ascertained in the context of this evaluation (PMID: 9215749, 20020534, 25326637, 9734640). Two ClinVar submitters have assessed the variant since 2014, including one expert panel (ClinGen Platelet Disorders Variant Curation Expert Panel): the expert panel classified the variant as uncertain significance, and the other submitter classified the variant as pathogenic. Based on the evidence outlined above, the variant was classified as likely pathogenic. -

Sep 01, 1998
OMIM
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:literature only

- -

not provided Pathogenic:1
Dec 18, 2024
GeneDx
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; This variant is associated with the following publications: (PMID: 20020534, 22513797, 25326637, 9734640, 37647632, 9215749, 34552732, 25373348) -

ITGA2B-related disorder Pathogenic:1
Jul 02, 2024
PreventionGenetics, part of Exact Sciences
Significance:Likely pathogenic
Review Status:no assertion criteria provided
Collection Method:clinical testing

The ITGA2B c.1787T>C variant is predicted to result in the amino acid substitution p.Ile596Thr. This variant has been reported in the compound heterozygous state and homozygous states in two patients with Glanzmann’s thrombasthenia (French et al. 1997. PubMed ID: 9215749). This variant is reported in 0.013% of alleles in individuals of European (Non-Finnish) descent in gnomAD and is interpreted as pathogenic by the ClinGen Platelet Disorders Variant Curation Expert Panel (https://www.ncbi.nlm.nih.gov/clinvar/variation/2900/). We interpret this variant as likely pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.83
BayesDel_addAF
Pathogenic
0.19
D
BayesDel_noAF
Pathogenic
0.27
CADD
Pathogenic
26
DANN
Uncertain
0.99
DEOGEN2
Benign
0.40
T
Eigen
Uncertain
0.40
Eigen_PC
Uncertain
0.26
FATHMM_MKL
Pathogenic
0.98
D
LIST_S2
Benign
0.82
T
M_CAP
Uncertain
0.26
D
MetaRNN
Pathogenic
0.99
D
MetaSVM
Uncertain
0.069
D
MutationAssessor
Pathogenic
3.5
H
PhyloP100
6.1
PrimateAI
Uncertain
0.57
T
PROVEAN
Pathogenic
-4.4
D
REVEL
Uncertain
0.63
Sift
Pathogenic
0.0
D
Sift4G
Pathogenic
0.0
D
Polyphen
1.0
D
Vest4
0.92
MutPred
0.95
Loss of stability (P = 0.0055);
MVP
0.87
MPC
1.1
ClinPred
0.57
D
GERP RS
3.8
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.7
Varity_R
0.97
gMVP
0.87
Mutation Taster
=38/62
disease causing

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

Other links and lift over

dbSNP: rs76811038; hg19: chr17-42457148; API