First Turkish case of Bernard-Soulier syndrome associated with GPIX N45S

Bernard-Soulier syndrome (BSS) is a rare bleeding disorder characterized by giant platelets, thrombocytopenia, and a prolonged bleeding time. It is caused by homozygous defects in the glycoprotein (GP) Ib/IX/V complex, which is the receptor for the von Willebrand factor. We examined a Turkish patient with suspected BSS to identify a molecular basis. Flow cytometric analysis revealed that platelet GPIb alpha and GPIX expression was markedly reduced and DNA sequence analysis showed a homozygous N45S missense mutation in the GPIX gene. Haplotype analysis revealed that the family had the same disease haplotype associated with the GPIX N45S commonly found in Northern European BSS. This is the first non-Caucasian Turkish BSS case due to GPIX N45S and is likely the result of a recurrent mutational event.