Supplementary Table S1:

Case55: GT65, French, 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.574+1G>A and NM_000419.3:c.1946+3G>T

LegacyVariant: N/A

ClinVar: N/A

CAiD: CA399805691 and CA626121071

gnomAD: MAF in the African population is 0.000 https://gnomad.broadinstitute.org/variant/17-42456008-C-A

Supplementary Table S1 & S2 Proband and Variant Information:

Case62: GT65, Female, 31 years old, French

DiseaseAssertion: Glanzmann thrombasthenia

FamilyInfo: N/A

ParentalGenotype: N/A

CasePresentingHPOs: HP:0000421, HP:0000225, HP:0000132, HP:0000790, HP:0002239, HP:0006298

(Epistaxis, gingival bleeding, menorrhagia, hematuria, GI bleeding, bleeding after dental procedure)

CaseHPOFreeText: Tonsil bleeding, muscle hematomas

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.574+1G>A and NM_000419.3:c.1946+3G>T

LegacyVariant: N/A

ClinVar: N/A

CAiD: CA399805691 and CA626121071

gnomAD: MAF in the European (non-Finnish) population is 0.00001235 https://gnomad.broadinstitute.org/variant/17-42462918-C-T and MAF in the African population is 0.000 https://gnomad.broadinstitute.org/variant/17-42456008-C-A

Case1: GTP1, gender, age, or ethnicity not specified

DiseaseAssertion: Glanzmann thrombasthenia

FamilyInfo: N/A

ParentalGenotype: Sequencing of both parental genomic DNA confirmed patient was homozygous for IVS4+1G>A mutation

CasePresentingHPOs: N/A

CaseHPOFreeText: N/A

CaseNotHPOs: N/A

CaseNotHPOsFreeText: N/A

ProteinExpression: Flow cytometry showed <5% αIIbβ3 expression, which was confirmed by western blot analysis

PlateletAggregation: N/A

CasePreviousTesting: Sequencing of patient genomic DNA was done on ITGA2B (no mention of ITGB3)

Gene: ITGA2B

Variant: NM_000419.3:c.574+1G>A (IVS4+1G>A)

LegacyVariant: N/A

ClinVar: N/A

CAiD: CA399805691

gnomAD: MAF in the European non-Finnish population 0.00001235 http://gnomad.broadinstitute.org/variant/17-42462918-C-T