Analysis of a family with β3(R760C)-related macrothrombocytopenia. (A) Family tree of the proband. Squares represent the male and circles represent the female family members. Arrow indicates the proband. Clinical status is indicated by the open (unaffected) or solid (affected) symbol. Age and platelet count are listed under each symbol. (B) May-Grünwald Giemsa staining of the proband peripheral blood film. Giant platelets are indicated by yellow arrows. (C) Surface GP expression levels in platelets were determined via flow cytometry. Data are shown as percentage expression relative to the father’s platelets (healthy control). (D) PAC-1 binding on platelets with or without agonists was detected via flow cytometry. (E) P-selectin (CD62P) expression with or without agonists was determined via flow cytometry. Representative results of 2 to 3 independent experiments are shown in panels C-E. (F) Genetic analysis of the proband and her father (control). Sequencing of platelet complementary DNA and genomic DNA revealed that the affected family members exhibited the heterozygous β3(R760C) mutation. MFI, mean fluorescence intensity; N.A., not available; y.o., years old.