Beschreibung:
<jats:p>We describe a new mutation in glycoprotein IX (GPIX) in a patient with Bernard–Soulier syndrome (BSS). Sequencing of GPIX revealed a homozygous (T→C) transition at nucleotide 1717 (GenBank/HUMGPIX/M80478), resulting in a Cys<jats:sup>8</jats:sup> (TGT)→Arg (CGT) replacement in the mature peptide. DNA restriction enzyme analysis using <jats:italic>Bsa</jats:italic>AI revealed that the patient was homozygous and that his parents were heterozygous for the defect. This mutation disrupts a putative disulphide bond between the Cys<jats:sup>8</jats:sup> and Cys<jats:sup>12</jats:sup> that would alter the secondary structure of GPIX and which probably accounts for the absence of the GPIb/IX/V complex from the platelet surface in this patient.</jats:p>