Supplementary Table S1 & S2 Proband and Variant Information:

Case34: GT36b, Male, 60 years old, Spanish

DiseaseAssertion: Glanzmann thrombasthenia

FamilyInfo: Affected sisters who are proband 36a and 36c in this study

ParentalGenotype: N/A

CasePresentingHPOs: HP:0004406

(Recurrent epistaxis)

CaseHPOFreeText: Embolism of the submaxillary artery

CaseNotHPOs: N/A

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.131G>T (p.Gly44Val) and NM_000419.3:c.1440-13_1440-1de (p.Arg480Serfs*106)

LegacyVariant: N/A

ClinVar: N/A

CAiD: CA399806881 and CA913184940

gnomAD: N/A

Supplementary Table S1 & S2 Proband and Variant Information:

Case33: GT36a, Female, 49 years old, Spanish

DiseaseAssertion: Glanzmann thrombasthenia

FamilyInfo: Affected brother who is proband 36b and affected sister who is proband 36c in this study

ParentalGenotype: N/A

CasePresentingHPOs: HP:0000421, HP:0000225

(Epistaxis, gingival bleeding)

CaseHPOFreeText: Bleeding at the onset of menses

CaseNotHPOs: N/A

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.131G>T (p.Gly44Val) and NM_000419.3:c.1440-13_1440-1de (p.Arg480Serfs*106)

LegacyVariant: N/A

ClinVar: N/A

CAiD: CA399806881 and CA913184940

gnomAD: N/A

Supplementary Table S1 & S2 Proband and Variant Information:

Case35: GT36c, Female, 47 years old, Spanish

DiseaseAssertion: Glanzmann thrombasthenia

FamilyInfo: Affected sister who is proband 36 a and affected brother proband 36b

ParentalGenotype: N/A

CasePresentingHPOs: HP:0000132, HP:0011891

(Menorrhagia, post-partum hemorrhage)

CaseHPOFreeText: Intra-abdominal hemorrhage and bleeding after trauma

CaseNotHPOs: N/A

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.131G>T (p.Gly44Val) and NM_000419.3:c.1440-13_1440-1de (p.Arg480Serfs*106)

LegacyVariant: N/A

ClinVar: N/A

CAiD: CA399806881 and CA913184940

gnomAD: N/A

Case1: GT-1, Female, Catalan, age not specified

DiseaseAssertion: Glanzmann thrombasthenia

FamilyInfo: Affected sister (GT-1) and brother (GT-3)

ParentalGenotype: N/A

CasePresentingHPOs: HP:0000421

(Epistaxis)

CaseHPOFreeText: Hemorrhage associated with deciduous tooth loss

CaseNotHPOs: N/A

CaseNotHPOsFreeText: N/A

ProteinExpression: Standard glycoprotein analysis confirmed the absence of αIIbβ3 in their platelets but while western blotting failed to reveal αIIb, residual β3 was at about 10% of usual levels and of normal migration (illustrated for GT1 in supplemental Figure 1).

PlateletAggregation: Platelets of all 3 patients failed to aggregate in response to a range of physiologic agonists but were agglutinated by ristocetin. Clot retraction was also defective.

CasePreviousTesting: Screened ITGA2B and ITGB3 genes of all three probands. Direct sequencing of all coding regions and splice sites of ITGA2B (30 exons) showed mutation.

Gene: ITGA2B

Variant: NM_000419.3:c.131G>T and NM_000419.3:c.1440-13_1440-1del

LegacyVariant: (p.Gly13Val)

ClinVar: N/A

CAiD: CA399806881 and CA913184940

gnomAD: N/A

Case3: GT-3, Male, Catalan, age not specified

DiseaseAssertion: Glanzmann thrombasthenia

FamilyInfo: Affected sisters (GT-1) and (GT-2)

ParentalGenotype: N/A

CasePresentingHPOs: HP:0000421

(Epistaxis)

CaseHPOFreeText: N/A

CaseNotHPOs: N/A

CaseNotHPOsFreeText: N/A

ProteinExpression: Standard glycoprotein analysis confirmed the absence of αIIbβ3 in their platelets but while western blotting failed to reveal αIIb, residual β3 was at about 10% of usual levels and of normal migration (illustrated for GT1 in supplemental Figure 1).

PlateletAggregation: Platelets of all 3 patients failed to aggregate in response to a range of physiologic agonists but were agglutinated by ristocetin. Clot retraction was also defective.

CasePreviousTesting: Screened ITGA2B and ITGB3 genes of all three probands. Direct sequencing of all coding regions and splice sites of ITGA2B (30 exons) showed mutation.

Gene: ITGA2B

Variant: NM_000419.3:c.131G>T and NM_000419.3:c.1440-13_1440-1del

LegacyVariant: (p.Gly13Val)

ClinVar: N/A

CAiD: CA399806881 and CA913184940

gnomAD: N/A

Case2: GT-2, Female, Catalan, age not specified

DiseaseAssertion: Glanzmann thrombasthenia

FamilyInfo: Affected sister (GT-1) and brother (GT-3)

ParentalGenotype: N/A

CasePresentingHPOs: HP:0011891

(Post-partum hemorrhage)

CaseHPOFreeText: N/A

CaseNotHPOs:

CaseNotHPOsFreeText:

ProteinExpression: Standard glycoprotein analysis confirmed the absence of αIIbβ3 in their platelets but while western blotting failed to reveal αIIb, residual β3 was at about 10% of usual levels and of normal migration (illustrated for GT1 in supplemental Figure 1).

PlateletAggregation: Platelets of all 3 patients failed to aggregate in response to a range of physiologic agonists but were agglutinated by ristocetin. Clot retraction was also defective.

CasePreviousTesting: Screened ITGA2B and ITGB3 genes of all three probands. Direct sequencing of all coding regions and splice sites of ITGA2B (30 exons) showed mutation.

Gene: ITGA2B

Variant: NM_000419.3:c.131G>T and NM_000419.3:c.1440-13_1440-1del

LegacyVariant: (p.Gly13Val)

ClinVar: N/A

CAiD: CA399806881 and CA913184940

gnomAD: N/A

Supplementary Table S1:

Case31: GT36a, Spain, gender and age not specified

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.131G>T (p.Gly44Val) and NM_000419.3:c.1440-13_1440-1del

LegacyVariant: N/A

ClinVar: N/A

CAiD: CA399806881 and CA913184940

gnomAD: N/A