Supplementary Table S1 & S2 Proband and Variant Information:

Case43: GT43a, Female, 7 years old, Moroccan (this proband died from epistaxis-see Supp Table S1)

DiseaseAssertion: Glanzmann thrombasthenia

FamilyInfo: Affected brother is 43b (See Supplementary Table S1)

ParentalGenotype: N/A

CasePresentingHPOs: HP:0000421

(Severe epistaxis)

CaseHPOFreeText: N/A

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: ITGB3

Variant: NM_000212.2:c.614+1G>T and NM_000212.2:c.683G>A (p.Arg228His)

LegacyVariant: N/A

ClinVar: N/A

CAiD: CA400023344 and CA8623025

gnomAD: MAF in the African population is 0.00008012 http://gnomad.broadinstitute.org/variant/17-45363694-G-A

Supplementary Table S1 & S2 Proband and Variant Information:

Case44: GT43b, Male, 11 years old, Morrocan

DiseaseAssertion: Glanzmann thrombasthenia

FamilyInfo: Affected sister is 43a (See Supplementary Table S1)

ParentalGenotype: N/A

CasePresentingHPOs: HP:0000421, HP:0000979, HP:0031364, HP:0000967, HP:0030137

(Epistaxis, purpura, ecchymosis, petechiae, prolonged bleeding at circumcision)

CaseHPOFreeText: N/A

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: ITGB3

Variant: NM_000212.2:c.614+1G>T and NM_000212.2:c.683G>A (p.Arg228His)

LegacyVariant: N/A

ClinVar: N/A

CAiD: CA400023344 and CA8623025

gnomAD: MAF in the African population is 0.00008012 http://gnomad.broadinstitute.org/variant/17-45363694-G-A

Supplementary Table S1 & S2 Proband and Variant Information:

Case44: GT43b, Male, 11 years old, Morrocan

DiseaseAssertion: Glanzmann thrombasthenia

FamilyInfo: Affected sister is 43a (See Supplementary Table S1)

ParentalGenotype: N/A

CasePresentingHPOs: HP:0000421, HP:0000979, HP:0031364, HP:0000967

(Epistaxis, purpura, ecchymosis, petechiae)

CaseHPOFreeText: Lots of bleeding at circumcision

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: ITGB3

Variant: NM_000212.2:c.614+1G>T and NM_000212.2:c.683G>A (p.Arg228His)

LegacyVariant: N/A

ClinVar: N/A

CAiD: CA400023344 and CA8623025

gnomAD: MAF in the African population is 0.00008012 http://gnomad.broadinstitute.org/variant/17-45363694-G-A

Supplementary Table S1:

Case37: GT43a, Morrocco, 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: ITGB3

Variant: NM_000212.2:c.614+1G>T and NM_000212.2:c.683G>A (p.Arg228His)

LegacyVariant: N/A

ClinVar: N/A

CAiD: CA400023344 and CA8623025

gnomAD: MAF in the African population is 0.00008012 https://gnomad.broadinstitute.org/variant/17-45363694-G-A