Novel mutations in GP IIb gene in Glanzmann's thrombasthenia from India.

The integrin GPIIb-IIIa plays an important role in platelet activation and plug formation. Quantitative and qualitative dysfunction in this receptor causes Glanzmann's thrombasthenia (GT) and leads to a bleeding tendency. Mutations in the GPIIb or GPIIIa gene are known to be responsible for the inherited form of this disease, which is characterized by mucocutaneous bleeding and other clinically severe bleeding manifestations. GT is an autosomal inherited platelet function. Mutations in the GPIIIa gene but not GPIIb gene in GT patients from Western India have been studied. Hence, this study was designed and included for the first time two mutation detection strategies: single strand conformation polymorphism and conformation sensitive gel electrophoresis followed by sequencing. Patients diagnosed as GT in our laboratory were screened for mutations. We report 12 mutations in 13 patients, of which 11 are novel mutations. Six mutations were missense, four were deletions and two were splice junction mutations. The study thus identifies novel mutations in the GPIIb gene in patients from Western India, implicating the importance of certain amino acids in structure-function correlations as well as enabling prenatal diagnosis in these families.