Supplementary Table S1 & S2 Proband and Variant Information:

Case6: GT7, Female, 19, French

DiseaseAssertion: Glanzmann thrombasthenia

FamilyInfo: 1 brother, that is all the information Supp table S1 gives us

ParentalGenotype: N/A

CasePresentingHPOs: HP:0000978 and HP:0000421

(Easy bruising and epistaxis)

CaseHPOFreeText: N/A

CaseNotHPOs: N/A

CaseNotHPOsFreeText: N/A

ProteinExpression: Flow cytometry showed <10-15% expression of αIIbβ3 (See Supplementary Table 1)

PlateletAggregation: Absent ADP but some response with other agonists (See Supplementary Table 1)

CasePreviousTesting: Sanger sequencing of ITGA2B and ITGB3

Gene: ITGB3

Variant: NM_000212.2:c.187C>T (p.Arg63Cys) and NM_000212.2:c.505C>T (p.Arg169Ter)

LegacyVariant: N/A

ClinVar: 631774

CAiD: CA8622892 and CA291224658

gnomAD: MAF in the East Asian population is 0.00005012 http://gnomad.broadinstitute.org/variant/17-45360741-C-T

Case#: Case 2, 20 yo Female

DiseaseAssertion: Glanzman thrombasthenia

ParentalGenotype: Not provided

CasePresentingHPOs: (HP:0000978, Bruising susceptibility) (HP:0000421, Epistaxis)

PlateletAggregation: Strong reduction of platelet aggregation with all agonists, except ristocetin. Normal platelet count.

CaseHPOFreeText:

CaseNotHPOs:

CaseNotHPOFreeText:

ProteinExpression: Flow cytometry, platelets with 18% to 24% residual αIIbβ3

CasePreviousTesting: Not provided

PreviouslyPublished: Not provided

Gene: ITGB3

HGVS: NM_000212.3:c.187C>T

ClinVar: 631774 https://www.ncbi.nlm.nih.gov/clinvar/variation/631774/

CAID: CA8622892

gnomAD: PopMax = 0.00002555 https://gnomad.broadinstitute.org/variant/17-47283375-C-T?dataset=gnomad_r4

Gene: ITGB3

HGVS: NM_000212.3:c.505C>T

ClinVar: 953061 https://www.ncbi.nlm.nih.gov/clinvar/variation/953061/

CAID: CA291224658

gnomAD: PopMax = 2.800e-7 https://gnomad.broadinstitute.org/variant/17-47284586-C-T?dataset=gnomad_r4