Supplementary Table S1 & S2 Proband and Variant Information:

Case31: GT35a, Female, 18 years old, USA

DiseaseAssertion: Glanzmann thrombasthenia

FamilyInfo: Affected sister who is 35 b in this study (See Supplementary Table S1)

ParentalGenotype: N/A

CasePresentingHPOs: HP:0000421, HP:0002239

(Epistaxis, GI bleeding)

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: ITGA2B and ITGB3

Variant: ITGB3: NM_000212.2:c.392G>C (p.Arg131Pro) and NM_000212.2:c.777+1G>A ITGA2B: NM_000419.3:c.2264G>A (p.Arg755Gln)

LegacyVariant: N/A

ClinVar: N/A

CAiD: CA8622954, CA8623036, CA8602771

gnomAD: MAF in the African population is 0.00006152 http://gnomad.broadinstitute.org/variant/17-45361839-G-C, MAF in the Latino population is 0.0006774 http://gnomad.broadinstitute.org/variant/17-45363789-G-A, MAF in the Latino population is 0.0001903 http://gnomad.broadinstitute.org/variant/17-42454380-C-T

Supplementary Table S1:

Case30: GT35a, USA, 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 and ITGB3

Variant: ITGA2B: NM_000419.3:c.2264G>A (p.Arg755Gln) NM_000212.2:c.392G>C (p.Arg131Pro) and NM_000212.2:c.777+1G>A

LegacyVariant: N/A

ClinVar: N/A

CAiD: CA8602771, CA8622954, CA8623036

gnomAD: MAF in the Latino population is 0.0001903 https://gnomad.broadinstitute.org/variant/17-42454380-C-T and MAF in the African population is 0.00006152 https://gnomad.broadinstitute.org/variant/17-45361839-G-C and MAF in the African population is 0.0006774 https://gnomad.broadinstitute.org/variant/17-45363789-G-A