شناسایی 5 جهش جدید در ژن گلیکوپروتئین Ibα پلاکت در بیماران برنارد- سولیر ایران

    Background & Aim: Bernard-Soulier syndrome (B.S.S) is a rare hereditary bleeding disorder due to molecular defects of platelet GPIb–IX–V. The GPIb-IX-V complex is composed of four chains of GPIbα, GPIbβ, GPIX and GPV.  The largest chain of this complex is GPIbα and is responsible for binding to ligand and most of identified mutations belong to this glycoprotein.  The aim of  this  study was to identify the molecular defects of GPIbα gene in Iranian Bernard-Soulier  patients. Patients and Method: Twelve Bernard-Soulier patients were selected from data base of bleeding disorders in Comprehensive Clinic of Iranian Hemophilia Center. Diagnostic criteria for B.S.S were based on phenotypic analysis such as platelet counts, inspection of peripheral blood smear and lack of response to restocetin agonist. Genomic DNA was isolated from blood leukocytes of the patients and their parents. The entire amino acid coding region in exon 2 from GPIbα was divided into five overlapping fragments and PCR amplification was done. Finally, sequence analysis of the coding regions that contain DNA heteroduplexes in CSGE gels was performed.Results: Sequence analysis revealed five novel mutations in GPIbα. The mutations include ACCGGCT deletion, GGA insertion in 419-425 position, missense mutations in T709C, G710A and C1759T, and the deletion of 20 nucleotides in 1800-1819 position. All five novel mutations were registered in International Gene Bank and for each mutation  RFLP (restriction fragment length polymorphism) design was created. Conclusion: In the present study, the molecular defects of GPIbα gene was investigated and five novel mutations were identified among Iranian BSS patients.