Figure 1.

Platelet phenotype and genotype of the index case. The platelet phenotype and genotype of the index case were assessed essentially as described elsewhere 2. (A) Platelet‐rich plasma (PRP) from the index case and a parallel control were prepared from citrated blood, and the platelet aggregation response to different agonists was assessed by standard light transmission aggregometry. The patient displayed abnormal platelet aggregation to all agonists, except ristocetin. A normal response (>90%) to all agonists was found in the control (not shown). (B) The expression of major platelet glycoproteins (GPs) was investigated in PRP from the patient and was controlled by flow cytometry with specific antibodies. Histograms show the severe reduction in α IIbβ3 integrin in the patient (P) compared to the control (C). Ig denotes labeling with an isotype antibody. The expression of other GPs (Ibα, IX, and Ia) (not shown) was similar to that of the control. (C) DNA was purified from the patient's blood. All the exon and flanking regions of ITGB3 and ITGA2B were PCR‐amplified with specific oligonucleotides and sequenced by the Sanger method. Mutations c.448A>G and c.774‐775delTG in the ITGB3 gene were found in the patient. (D) Family pedigree, with identification of carriers of mutations. The patient's father and one sister had died before the study commenced. NA: not available for analysis.