Case2: Patient 2, Male, 4 years old

DiseaseAssertion: Glanzmann thrombasthenia

FamilyInfo: Affected brother is Patient 1

ParentalGenotype: Mother and father revealed heterozygosity for c.1878G>C mutation. (Parents are consanguineous)

CasePresentingHPOs: HP:0000967 (Petechiae)

CaseHPOFreeText: Hematomas, prolonged in vitro bleeding time

CaseNotHPOs: N/A

CaseNotHPOsFreeText: N/A

ProteinExpression: Flow cytometry analysis revealed that there was 109 of GPIIb/IIIa expression for Patient 2

PlateletAggregation: All patients' platelets showed severely reduced platelet aggregation after stimulation with collagen and ADP in contrast to the normal range (See Table 1). Stimulation with epinephrine and arachidonic acid also demonstrated decreased platelet aggregation. In contrast, ristocetin-induced platelet aggregation was borderline for Patient 2

CasePreviousTesting: Sequenced ITGA2B and ITGB3 genes from one patient of each family (Patient 2 and 3) and Patient 1 and 4 were screened for the identified mutation in the corresponding family.

Gene: ITGA2B

Variant: NM_000419.3:c.1878G>C (p.Gln626His)

LegacyVariant: N/A

ClinVar: 2903

CAiD: CA115852

gnomAD: N/A

Case1: Patient 1, Male, 6 years old

DiseaseAssertion: Glanzmann thrombasthenia

FamilyInfo: Affected brother is Patient 2

ParentalGenotype: Mother and father revealed heterozygosity for c.1878G>C mutation. (Parents are consanguineous)

CasePresentingHPOs: HP:0000967, HP:0000421, HP:0000225

(Petechiae, epistaxis, gingival bleeding)

CaseHPOFreeText: Hematomas,

CaseNotHPOs: N/A

CaseNotHPOsFreeText: N/A

ProteinExpression: Flow cytometry analysis showed that there was no surface expression of GPIIb/IIIa detectable on patient 1's platelets, indicating a lack of platelet GPIIb/IIIa expression

PlateletAggregation: All patients' platelets showed severely reduced platelet aggregation after stimulation with collagen and ADP in contrast to the normal range (See Table 1). Stimulation with epinephrine and arachidonic acid also demonstrated decreased platelet aggregation. In contrast, ristocetin-induced platelet aggregation was within normal range for patient 1

CasePreviousTesting: Sequenced ITGA2B and ITGB3 genes from one patient of each family (Patient 2 and 3) and Patient 1 and 4 were screened for the identified mutation in the corresponding family.

Gene: ITGA2B

Variant: NM_000419.3:c.1878G>C (p.Gln626His)

LegacyVariant: N/A

ClinVar: 2903

CAiD: CA115852

gnomAD: N/A

Supplementary Table S1 & S2 Proband and Variant Information:

Case66: GT69, Female, 32 years old, French

DiseaseAssertion: Glanzmann thrombasthenia

FamilyInfo: N/A

ParentalGenotype: N/A

CasePresentingHPOs: HP:0000978, HP:0000979, HP:0004406, HP:0000132, HP:0004846

(Bruising, purpura, recurrent epistaxis, menorrhagia, prolonged bleeding after surgery)

CaseHPOFreeText: N/A

CaseNotHPOs: HP:0006298 (Prolonged bleeding after dental extraction)

CaseNotHPOsFreeText: N/A

ProteinExpression: Flow cytometry showed <5% expression of αIIbβ3 (See Supplementary Table 1)

PlateletAggregation: Absent platelet aggregation (See Supplementary Table 1)

CasePreviousTesting: Sanger sequencing of ITGA2B and ITGB3

Gene: ITGA2B

Variant: NM_000419.3:c.1878G>C (p.Gln626His)

LegacyVariant: N/A

ClinVar: 2903

CAiD: CA115852

gnomAD: N/A

Case7: Patient HA, gender, age and ethnicity not specified

DiseaseAssertion: Glanzmann thrombasthenia type I

FamilyInfo: N/A

ParentalGenotype: N/A

CasePresentingHPOs: N/A

CaseHPOFreeText: Bleeding symptoms were evaluated by examining available hospital records. Mild bleeders were defined as those who had minor symptoms, such as epistaxis or gum bleeds, and moderate bleeders suffered, in addition, from bleeding complications after surgery and trauma. Severe bleeders were defined as those with a history of spontaneous or life-threatening hemorrhages, such as gastrointestinal bleeding, or who had repeated episodes requiring platelet transfusion. See Table 1.

CaseNotHPOs: N/A

CaseNotHPOsFreeText: N/A

ProteinExpression: See Table 6

PlateletAggregation: See Table 6

CasePreviousTesting: To ascertain the mutations, we sequenced the coding regions of the αIIb and β3 subunits including the exon/intron boundaries

Gene: ITGA2B

Variant: NM_000419.3:c.1878G>C

LegacyVariant: N/A

ClinVar: 2903

CAiD: CA115852

gnomAD: N/A

Case5: Patient HM, gender, age and ethnicity not specified

DiseaseAssertion: Glanzmann thrombasthenia type I

FamilyInfo: N/A

ParentalGenotype: N/A

CasePresentingHPOs: N/A

CaseHPOFreeText: Bleeding symptoms were evaluated by examining available hospital records. Mild bleeders were defined as those who had minor symptoms, such as epistaxis or gum bleeds, and moderate bleeders suffered, in addition, from bleeding complications after surgery and trauma. Severe bleeders were defined as those with a history of spontaneous or life-threatening hemorrhages, such as gastrointestinal bleeding, or who had repeated episodes requiring platelet transfusion. See Table 1.

CaseNotHPOs: N/A

CaseNotHPOsFreeText: N/A

ProteinExpression: See Table 6

PlateletAggregation: See Table 6

CasePreviousTesting: To ascertain the mutations, we sequenced the coding regions of the αIIb and β3 subunits including the exon/intron boundaries

Gene: ITGA2B

Variant: NM_000419.3:c.1878G>C

LegacyVariant: N/A

ClinVar: 2903

CAiD: CA115852

gnomAD: N/A

Case6: Patient HS, gender, age and ethnicity not specified

DiseaseAssertion: Glanzmann thrombasthenia type I

FamilyInfo: N/A

ParentalGenotype: N/A

CasePresentingHPOs: N/A

CaseHPOFreeText: Bleeding symptoms were evaluated by examining available hospital records. Mild bleeders were defined as those who had minor symptoms, such as epistaxis or gum bleeds, and moderate bleeders suffered, in addition, from bleeding complications after surgery and trauma. Severe bleeders were defined as those with a history of spontaneous or life-threatening hemorrhages, such as gastrointestinal bleeding, or who had repeated episodes requiring platelet transfusion. See Table 1.

CaseNotHPOs: N/A

CaseNotHPOsFreeText: N/A

ProteinExpression: See Table 6

PlateletAggregation: See Table 6

CasePreviousTesting: To ascertain the mutations, we sequenced the coding regions of the αIIb and β3 subunits including the exon/intron boundaries

Gene: ITGA2B

Variant: NM_000419.3:c.1878G>C

LegacyVariant: N/A

ClinVar: 2903

CAiD: CA115852

gnomAD: N/A

Case10: (Proband CabGT-10) Female, age not specifie,d North African

DiseaseAssertion: Glanzmann thrombasthenia

FamilyInfo: N/A

ParentalGenotype: N/A

CasePresentingHPOs: N/A

CaseHPOFreeText: N/A

CaseNotHPOs: N/A

ProteinExpression: Flow cytometry showed <5% GPIIIa and GPIIb surface expression

Platelet Aggregation: N/A

CasePreviousTesting: Promoter and exon sequences of aIIb and b3 genes were amplified and directly sequence

Gene: ITGA2B

Variant: NM_000419.3:c.1878G>C (p.Gln626His)

LegacyVariant: N/A

ClinVar: 2903

CAiD: CA115852

gnomAD N/A

Supplementary Table S1:

Case59: GT69, French, age and gender are not specified here

DiseaseAssertion: Glanzmann thrombasthenia type I

FamilyInfo: N/A

ParentalGenotype: N/A

CasePresentingHPOs: N/A

CaseHPOFreeText: All patients had a life-long history of mucocutaneous bleeding

CaseNotHPOs: N/A

CaseNotHPOsFreeText: N/A

ProteinExpression: All patients in this study met the clinical and platelet function requirements for GT-- this includes an absent or strongly reduced expression of alphaIIbBeta3 in platelets

PlateletAggregation: All patients in this study met the clinical and platelet function requirements for GT-- this includes absent or severely reduced platelet aggregation with at least three physiological agonists

CasePreviousTesting: Sanger sequencing was performed. Sanger sequencing ensured coverage of all exons and splice sties of the ITGA2B and ITGB3 genes and extended 300-500 bp into the introns as well as including the UTR. They sequenced 416 bp upstream of the ITGA2B promoter and 463 bp upstream of the ITGB3 promoter. In total they sequenced 51.2% of the ITGA2B gene and 19.4% of the larger ITGB3 gene

Gene: ITGA2B

Variant: NM_000419.3:c.1878G>C (p.Gln626His/ p.Asp585_Gln626del)

LegacyVariant: N/A

ClinVar: 2903

CAiD: CA115852

gnomAD: N/A